.. _moduleInterval:

music21.interval
================

.. WARNING: DO NOT EDIT THIS FILE: AUTOMATICALLY GENERATED.  Edit the .py file directly

.. module:: music21.interval

This module defines various types of interval objects. Fundamental classes are :class:`~music21.interval.Interval`, :class:`~music21.interval.GenericInterval`, and :class:`~music21.interval.ChromaticInterval`. Numerous utility functions are provided for processing and generating intervals. *module authors: Michael Scott Cuthbert, Jackie Rogoff, Amy Hailes, and Christopher Ariza* 




.. function:: notesToChromatic(n1, n2)

    Given two :class:`~music21.note.Note` objects, returns a :class:`~music21.interval.ChromaticInterval` object. Works equally well with :class:`~music21.pitch.Pitch` objects. 

    >>> from music21 import *
    >>> aNote = note.Note('c4')
    >>> bNote = note.Note('g#5')
    >>> notesToChromatic(aNote, bNote)
    <music21.interval.ChromaticInterval 20> 
    >>> aPitch = pitch.Pitch('c#4')
    >>> bPitch = pitch.Pitch('f-5')
    >>> bInterval = notesToChromatic(aPitch, bPitch)
    >>> bInterval
    <music21.interval.ChromaticInterval 15> 

    

.. function:: intervalsToDiatonic(gInt, cInt)

    Given a :class:`~music21.interval.GenericInterval` and a :class:`~music21.interval.ChromaticInterval` object, return a :class:`~music21.interval.DiatonicInterval`. 

    >>> from music21 import *
    >>> aInterval = interval.GenericInterval('descending fifth')
    >>> bInterval = interval.ChromaticInterval(-7)
    >>> cInterval = interval.intervalsToDiatonic(aInterval, bInterval)
    >>> cInterval
    <music21.interval.DiatonicInterval P5> 

.. function:: intervalFromGenericAndChromatic(gInt, cInt)

    Given a :class:`~music21.interval.GenericInterval` and a :class:`~music21.interval.ChromaticInterval` object, return a full :class:`~music21.interval.Interval`. 

    >>> from music21 import *
    >>> aInterval = interval.GenericInterval('descending fifth')
    >>> bInterval = interval.ChromaticInterval(-8)
    >>> cInterval = interval.intervalFromGenericAndChromatic(aInterval, bInterval)
    >>> cInterval
    <music21.interval.Interval A-5> 
    >>> cInterval.directedNiceName
    'Descending Augmented Fifth' 

.. function:: add(intervalList)

    add a list of intervals and return the composite interval Intervals can be Interval objects or just strings. (Currently not particularly efficient for large lists...) 

    

    >>> from music21 import *
    >>> A2 = interval.Interval('A2')
    >>> P5 = interval.Interval('P5')
    >>> interval.add([A2, P5])
    <music21.interval.Interval A6> 
    >>> interval.add([P5, "m2"])
    <music21.interval.Interval m6> 
    >>> interval.add(["W","W","H","W","W","W","H"])
    <music21.interval.Interval P8> 

    
    Direction does matter: 

    
    >>> interval.add([P5, "P-4"])
    <music21.interval.Interval M2> 

.. function:: convertDiatonicNumberToStep(dn)

    Convert a diatonic number to a step name (without accidental) and a octave integer. The lowest C on a Bosendorfer Imperial Grand is assigned 1 the D above it is 2, E is 3, etc.  See pitch.diatonicNoteNum for more details 

    >>> from music21 import *
    >>> interval.convertDiatonicNumberToStep(15)
    ('C', 2) 
    >>> interval.convertDiatonicNumberToStep(23)
    ('D', 3) 
    >>> interval.convertDiatonicNumberToStep(0)
    ('B', -1) 
    >>> interval.convertDiatonicNumberToStep(1)
    ('C', 0) 

    
    Extremely high and absurdly low numbers also produce "notes". 

    
    >>> interval.convertDiatonicNumberToStep(2100)
    ('B', 299) 
    >>> interval.convertDiatonicNumberToStep(-19)
    ('D', -3) 

    

.. function:: convertGeneric(value)

    Convert an interval specified in terms of its name (second, third) into an integer. If integers are passed, assume the are correct. 

    >>> from music21 import *
    >>> interval.convertGeneric(3)
    3 
    >>> interval.convertGeneric('third')
    3 
    >>> interval.convertGeneric('3rd')
    3 
    >>> interval.convertGeneric('octave')
    8 
    >>> interval.convertGeneric('twelfth')
    12 
    >>> interval.convertGeneric('descending twelfth')
    -12 
    >>> interval.convertGeneric(12)
    12 
    >>> interval.convertGeneric(-12)
    -12 
    >>> interval.convertGeneric(1)
    1 
    >>> interval.convertGeneric(None)
    Traceback (most recent call last): 
    IntervalException: Cannot get a direction from None 
    >>> interval.convertGeneric("1")
    Traceback (most recent call last): 
    IntervalException: Cannot get a direction from 1 

.. function:: convertGenericToSemitone(value)

    Convert a generic specification into an interval count. This uses a default mapping. 

.. function:: convertSemitoneToSpecifierGeneric(count)

    Given a number of semitones, return a default diatonic specifier. 

    >>> from music21 import *
    >>> interval.convertSemitoneToSpecifierGeneric(0)
    ('P', 1) 
    >>> interval.convertSemitoneToSpecifierGeneric(-2)
    ('M', -2) 
    >>> interval.convertSemitoneToSpecifierGeneric(1)
    ('m', 2) 
    >>> interval.convertSemitoneToSpecifierGeneric(7)
    ('P', 5) 
    >>> interval.convertSemitoneToSpecifierGeneric(11)
    ('M', 7) 
    >>> interval.convertSemitoneToSpecifierGeneric(12)
    ('P', 8) 
    >>> interval.convertSemitoneToSpecifierGeneric(13)
    ('m', 9) 
    >>> interval.convertSemitoneToSpecifierGeneric(-15)
    ('m', -10) 
    >>> interval.convertSemitoneToSpecifierGeneric(24)
    ('P', 15) 

.. function:: convertSpecifier(specifier)

    Given an integer or a string representing a "specifier" (major, minor, perfect, diminished, etc.), return a tuple of (1) an integer which refers to the appropriate specifier in a list and (2) a standard form for the specifier. This function permits specifiers to specified in a flexible manner. 

    >>> from music21 import *
    >>> interval.convertSpecifier(3)
    (3, 'm') 
    >>> interval.convertSpecifier('p')
    (1, 'P') 
    >>> interval.convertSpecifier('P')
    (1, 'P') 
    >>> interval.convertSpecifier('M')
    (2, 'M') 
    >>> interval.convertSpecifier('major')
    (2, 'M') 
    >>> interval.convertSpecifier('m')
    (3, 'm') 
    >>> interval.convertSpecifier('Augmented')
    (4, 'A') 
    >>> interval.convertSpecifier('a')
    (4, 'A') 
    >>> interval.convertSpecifier(None)
    (None, None) 

.. function:: convertStaffDistanceToInterval(staffDist)

    Returns an integer of the generic interval number (P5 = 5, M3 = 3) etc. from the given staff distance. 

    >>> from music21 import *
    >>> interval.convertStaffDistanceToInterval(3)
    4 
    >>> interval.convertStaffDistanceToInterval(7)
    8 
    >>> interval.convertStaffDistanceToInterval(0)
    1 
    >>> interval.convertStaffDistanceToInterval(-1)
    -2 

.. function:: getAbsoluteHigherNote(note1, note2)

    Given two :class:`~music21.note.Note` objects, returns the higher note based on actual pitch. If both pitches are the same, returns the first note given. 

    >>> from music21 import *
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d--3')
    >>> interval.getAbsoluteHigherNote(aNote, bNote)
    <music21.note.Note C#> 

    

.. function:: getAbsoluteLowerNote(note1, note2)

    Given two :class:`~music21.note.Note` objects, returns the lower note based on actual pitch. If both pitches are the same, returns the first note given. 

    >>> from music21 import *
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d--3')
    >>> interval.getAbsoluteLowerNote(aNote, bNote)
    <music21.note.Note D--> 

.. function:: getWrittenHigherNote(note1, note2)

    Given two :class:`~music21.note.Note` or :class:`~music21.pitch.Pitch` objects, this function returns the higher object based on diatonic note numbers. Returns the note higher in pitch if the diatonic number is the same, or the first note if pitch is also the same. 

    >>> from music21 import *
    >>> cis = pitch.Pitch("C#")
    >>> deses = pitch.Pitch("D--")
    >>> higher = interval.getWrittenHigherNote(cis, deses)
    >>> higher is deses
    True 

    
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d-3')
    >>> interval.getWrittenHigherNote(aNote, bNote)
    <music21.note.Note D-> 
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d--3')
    >>> interval.getWrittenHigherNote(aNote, bNote)
    <music21.note.Note D--> 

.. function:: getWrittenLowerNote(note1, note2)

    Given two :class:`~music21.note.Note` objects, returns the lower note based on diatonic note number. Returns the note lower in pitch if the diatonic number is the same, or the first note if pitch is also the same. 

    >>> from music21 import *
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d--3')
    >>> interval.getWrittenLowerNote(aNote, bNote)
    <music21.note.Note C#> 
    >>> aNote = note.Note('c#3')
    >>> bNote = note.Note('d-3')
    >>> interval.getWrittenLowerNote(aNote, bNote)
    <music21.note.Note C#> 

.. function:: notesToGeneric(n1, n2)

    Given two :class:`~music21.note.Note` objects, returns a :class:`~music21.interval.GenericInterval` object. works equally well with :class:`~music21.pitch.Pitch` objects 

    >>> from music21 import *
    >>> aNote = note.Note('c4')
    >>> bNote = note.Note('g5')
    >>> aInterval = notesToGeneric(aNote, bNote)
    >>> aInterval
    <music21.interval.GenericInterval 12> 
    >>> aPitch = pitch.Pitch('c#4')
    >>> bPitch = pitch.Pitch('f-5')
    >>> bInterval = notesToGeneric(aPitch, bPitch)
    >>> bInterval
    <music21.interval.GenericInterval 11> 

    

.. function:: notesToInterval(n1, n2=None)

    Given two :class:`~music21.note.Note` objects, returns an :class:`~music21.interval.Interval` object. The same functionality is available by calling the Interval class with two Notes as arguments. Works equally well with :class:`~music21.pitch.Pitch` objects. 

    >>> from music21 import *
    >>> aNote = note.Note('c4')
    >>> bNote = note.Note('g5')
    >>> aInterval = interval.notesToInterval(aNote, bNote)
    >>> aInterval
    <music21.interval.Interval P12> 
    >>> bInterval = interval.Interval(noteStart=aNote, noteEnd=bNote)
    >>> aInterval.niceName == bInterval.niceName
    True 
    >>> aPitch = pitch.Pitch('c#4')
    >>> bPitch = pitch.Pitch('f-5')
    >>> cInterval = interval.notesToInterval(aPitch, bPitch)
    >>> cInterval
    <music21.interval.Interval dd11> 
    >>> cPitch = pitch.Pitch('e#4')
    >>> dPitch = pitch.Pitch('f-4')
    >>> dInterval = interval.notesToInterval(cPitch, dPitch)
    >>> dInterval
    <music21.interval.Interval dd2> 
    >>> ePitch = pitch.Pitch('e##4')
    >>> fPitch = pitch.Pitch('f--4')
    >>> dInterval = interval.notesToInterval(ePitch, fPitch)
    >>> dInterval
    <music21.interval.Interval dddd2> 
    >>> gPitch = pitch.Pitch('c--4')
    >>> hPitch = pitch.Pitch('c##4')
    >>> iInterval = interval.notesToInterval(gPitch, hPitch)
    >>> iInterval
    <music21.interval.Interval AAAA1> 
    >>> interval.notesToInterval(pitch.Pitch('e##4'), pitch.Pitch('f--5'))
    <music21.interval.Interval dddd9> 

    

.. function:: subtract(intervalList)

    starts with the first interval and subtracts the following intervals from it: 

    >>> from music21 import *
    >>> interval.subtract(["P5","M3"])
    <music21.interval.Interval m3> 
    >>> interval.subtract(["P4","d3"])
    <music21.interval.Interval A2> 
    >>> m2Object = interval.Interval("m2")
    >>> interval.subtract(["M6","m2",m2Object])
    <music21.interval.Interval AA4> 
    >>> interval.subtract(["P4", "M-2"])
    <music21.interval.Interval P5> 
    >>> interval.subtract(["A2","A2"])
    <music21.interval.Interval P1> 
    >>> interval.subtract(["A1","P1"])
    <music21.interval.Interval A1> 
    >>> a = interval.subtract(["P5","A5"])
    >>> a.niceName
    'Augmented Unison' 
    >>> a.chromatic.semitones
    -1 

    
    BUG: should be Descending Augmented Unison, currently giving Oblique Augmented Unison ! AARGH 

    

    

.. function:: transposeNote(note1, intervalString)

    Given a :class:`~music21.note.Note` and a interval string (such as 'P5') or an Interval object, return a new Note object at the appropriate pitch level. 

    >>> from music21 import *
    >>> aNote = note.Note('c4')
    >>> bNote = interval.transposeNote(aNote, 'p5')
    >>> bNote
    <music21.note.Note G> 
    >>> bNote.pitch
    G4 
    >>> aNote = note.Note('f#4')
    >>> bNote = interval.transposeNote(aNote, 'm2')
    >>> bNote
    <music21.note.Note G> 

    

.. function:: transposePitch(pitch1, interval1)

    Given a :class:`~music21.pitch.Pitch` and a :class:`~music21.interval.Interval` object, return a new Pitch object at the appropriate pitch level. 

    >>> from music21 import *
    >>> aPitch = pitch.Pitch('C4')
    >>> aInterval = interval.Interval('P5')
    >>> bPitch = interval.transposePitch(aPitch, aInterval)
    >>> bPitch
    G4 
    >>> bInterval = interval.Interval('P-5')
    >>> cPitch = interval.transposePitch(aPitch, bInterval)
    >>> cPitch
    F3 

Interval
--------

Inherits from: :class:`~music21.base.Music21Object`, :class:`~music21.base.JSONSerializer`

.. class:: Interval(*arguments, **keywords)

    An Interval class that encapsulates both Chromatic and Diatonic intervals all in one model. The interval is specified either as named arguments, a :class:`~music21.interval.DiatonicInterval` and a :class:`~music21.interval.ChromaticInterval`, or two :class:`~music21.note.Note` objects, from which both a ChromaticInterval and DiatonicInterval are derived. 

    >>> from music21 import *
    >>> n1 = note.Note('c3')
    >>> n2 = note.Note('c5')
    >>> aInterval = interval.Interval(noteStart=n1, noteEnd=n2)
    >>> aInterval
    <music21.interval.Interval P15> 

    
    Two Intervals are the same if their Chromatic and Diatonic intervals 
    are the same.  N.B. that interval.Interval('a4') != 'a4' -- maybe it should... 

    

    

    >>> from music21 import *
    >>> aInterval = interval.Interval('m3')
    >>> aInterval
    <music21.interval.Interval m3> 
    >>> aInterval = interval.Interval('M3')
    >>> aInterval
    <music21.interval.Interval M3> 
    >>> aInterval = interval.Interval('p5')
    >>> aInterval
    <music21.interval.Interval P5> 
    >>> aInterval.isChromaticStep
    False 
    >>> aInterval.isDiatonicStep
    False 
    >>> aInterval.isStep
    False 
    >>> aInterval = interval.Interval('half')
    >>> aInterval
    <music21.interval.Interval m2> 
    >>> aInterval.isChromaticStep
    True 
    >>> aInterval.isDiatonicStep
    True 
    >>> aInterval.isStep
    True 
    >>> aInterval = interval.Interval('-h')
    >>> aInterval
    <music21.interval.Interval m-2> 
    >>> aInterval = interval.Interval(3)
    >>> aInterval
    <music21.interval.Interval m3> 
    >>> aInterval = interval.Interval(7)
    >>> aInterval
    <music21.interval.Interval P5> 

    
    >>> n1 = note.Note('c3')
    >>> n2 = note.Note('g3')
    >>> aInterval = interval.Interval(noteStart=n1, noteEnd=n2)
    >>> aInterval
    <music21.interval.Interval P5> 
    >>> aInterval = interval.Interval(noteStart=n1, noteEnd=None)
    Traceback (most recent call last): 
    IntervalException: either both the starting and the ending note.Note must be given or neither can be given.  You cannot have one without the other. 
    >>> aInterval = interval.DiatonicInterval('major', 'third')
    >>> bInterval = interval.ChromaticInterval(4)
    >>> cInterval = interval.Interval(diatonic=aInterval, chromatic=bInterval)
    >>> cInterval
    <music21.interval.Interval M3> 
    >>> cInterval = interval.Interval(diatonic=aInterval, chromatic=None)
    Traceback (most recent call last): 
    IntervalException: either both a DiatonicInterval and a ChromaticInterval object have to be given or neither can be given.  You cannot have one without the other. 

    

    **Interval** **attributes**

        Attributes without Documentation: `chromatic`, `diatonic`, `diatonicType`, `direction`, `generic`, `niceName`, `type`

        Attributes inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.classSortOrder`, :attr:`~music21.base.Music21Object.hideObjectOnPrint`, :attr:`~music21.base.Music21Object.id`, :attr:`~music21.base.Music21Object.groups`

    **Interval** **properties**

        .. attribute:: complement

            Return a new Interval object that is the complement of this Interval. 

            >>> from music21 import *
            >>> aInterval = interval.Interval('M3')
            >>> bInterval = aInterval.complement
            >>> bInterval
            <music21.interval.Interval m6> 
            >>> cInterval = interval.Interval('A2')
            >>> dInterval = cInterval.complement
            >>> dInterval
            <music21.interval.Interval d7> 

        .. attribute:: intervalClass

            Return the interval class from the chromatic interval. 

            >>> from music21 import *
            >>> aInterval = interval.Interval('M3')
            >>> aInterval.intervalClass
            4 

        .. attribute:: noteEnd

            Assuming this Interval has been defined, set the end note (_noteEnd) to a new value; this will adjust the value of the start note (_noteStart). 

            >>> from music21 import *
            >>> aInterval = interval.Interval('M3')
            >>> aInterval.noteEnd = note.Note('e4')
            >>> aInterval.noteStart.nameWithOctave
            'C4' 
            >>> aInterval = interval.Interval('m2')
            >>> aInterval.noteEnd = note.Note('A#3')
            >>> aInterval.noteStart.nameWithOctave
            'G##3' 
            >>> n1 = note.Note('g#3')
            >>> n2 = note.Note('c3')
            >>> aInterval = interval.Interval(n1, n2)
            >>> aInterval.directedName # downward augmented fifth
            'A-5' 
            >>> aInterval.noteEnd = note.Note('c4')
            >>> aInterval.noteStart.nameWithOctave
            'G#4' 
            >>> aInterval = interval.Interval('M3')
            >>> aInterval.noteEnd = note.Note('A-3')
            >>> aInterval.noteStart.nameWithOctave
            'F-3' 

            

        .. attribute:: noteStart

            Assuming this Interval has been defined, set the start note (_noteStart) to a new value; this will adjust the value of the end note (_noteEnd). 

            >>> from music21 import *
            >>> aInterval = interval.Interval('M3')
            >>> aInterval.noteStart = note.Note('c4')
            >>> aInterval.noteEnd.nameWithOctave
            'E4' 
            >>> n1 = note.Note('c3')
            >>> n2 = note.Note('g#3')
            >>> aInterval = interval.Interval(n1, n2)
            >>> aInterval.name
            'A5' 
            >>> aInterval.noteStart = note.Note('g4')
            >>> aInterval.noteEnd.nameWithOctave
            'D#5' 
            >>> aInterval = interval.Interval('-M3')
            >>> aInterval.noteStart = note.Note('c4')
            >>> aInterval.noteEnd.nameWithOctave
            'A-3' 
            >>> aInterval = interval.Interval('M-2')
            >>> aInterval.noteStart = note.Note('A#3')
            >>> aInterval.noteEnd.nameWithOctave
            'G#3' 
            >>> aInterval = interval.Interval('h')
            >>> aInterval.directedName
            'm2' 
            >>> aInterval.noteStart = note.Note('F#3')
            >>> aInterval.noteEnd.nameWithOctave
            'G3' 

            

        Properties inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.activeSite`, :attr:`~music21.base.Music21Object.beat`, :attr:`~music21.base.Music21Object.beatDuration`, :attr:`~music21.base.Music21Object.beatStr`, :attr:`~music21.base.Music21Object.beatStrength`, :attr:`~music21.base.Music21Object.classes`, :attr:`~music21.base.Music21Object.derivationHierarchy`, :attr:`~music21.base.Music21Object.duration`, :attr:`~music21.base.Music21Object.measureNumber`, :attr:`~music21.base.Music21Object.offset`, :attr:`~music21.base.Music21Object.priority`

        Properties inherited from :class:`~music21.base.JSONSerializer`: :attr:`~music21.base.JSONSerializer.json`

    **Interval** **methods**

        .. method:: reinit()

            Reinitialize the internal interval objects in case something has changed. Called during __init__ to assign attributes. 

        .. method:: reverse()

            Return an reversed version of this interval. If given Notes, these notes are reversed. 

            >>> from music21 import *
            >>> n1 = note.Note('c3')
            >>> n2 = note.Note('g3')
            >>> aInterval = interval.Interval(noteStart=n1, noteEnd=n2)
            >>> aInterval
            <music21.interval.Interval P5> 
            >>> bInterval = aInterval.reverse()
            >>> bInterval
            <music21.interval.Interval P-5> 
            >>> bInterval.noteStart == aInterval.noteEnd
            True 
            >>> aInterval = interval.Interval('m3')
            >>> aInterval.reverse()
            <music21.interval.Interval m-3> 

        .. method:: transposePitch(p, reverse=False, clearAccidentalDisplay=True, maxAccidental=4)

            Given a :class:`~music21.pitch.Pitch`  object, return a new, transposed Pitch, that is transformed according to this Interval. This is the main public interface to all transposition routines found on higher-level objects. The `maxAccidental` parameter sets an integer number of half step alterations that will be accepted in the transposed pitch. For example, a value of 2 will permit double sharps but not triple sharps. 

            >>> from music21 import *
            >>> p1 = pitch.Pitch('a#')
            >>> i = interval.Interval('m3')
            >>> p2 = i.transposePitch(p1)
            >>> p2
            C#5 
            >>> p2 = i.transposePitch(p1, reverse=True)
            >>> p2
            F##4 
            >>> i.transposePitch(p1, reverse=True, maxAccidental=1)
            G4 

        Methods inherited from :class:`~music21.base.Music21Object`: :meth:`~music21.base.Music21Object.searchParentByAttr`, :meth:`~music21.base.Music21Object.getContextAttr`, :meth:`~music21.base.Music21Object.setContextAttr`, :meth:`~music21.base.Music21Object.addContext`, :meth:`~music21.base.Music21Object.addLocation`, :meth:`~music21.base.Music21Object.addLocationAndActiveSite`, :meth:`~music21.base.Music21Object.freezeIds`, :meth:`~music21.base.Music21Object.getAllContextsByClass`, :meth:`~music21.base.Music21Object.getCommonSiteIds`, :meth:`~music21.base.Music21Object.getCommonSites`, :meth:`~music21.base.Music21Object.getContextByClass`, :meth:`~music21.base.Music21Object.getOffsetBySite`, :meth:`~music21.base.Music21Object.getSiteIds`, :meth:`~music21.base.Music21Object.getSites`, :meth:`~music21.base.Music21Object.getSpannerSites`, :meth:`~music21.base.Music21Object.hasContext`, :meth:`~music21.base.Music21Object.mergeAttributes`, :meth:`~music21.base.Music21Object.purgeLocations`, :meth:`~music21.base.Music21Object.removeLocationBySite`, :meth:`~music21.base.Music21Object.removeLocationBySiteId`, :meth:`~music21.base.Music21Object.setOffsetBySite`, :meth:`~music21.base.Music21Object.show`, :meth:`~music21.base.Music21Object.splitAtDurations`, :meth:`~music21.base.Music21Object.splitAtQuarterLength`, :meth:`~music21.base.Music21Object.splitByQuarterLengths`, :meth:`~music21.base.Music21Object.unfreezeIds`, :meth:`~music21.base.Music21Object.unwrapWeakref`, :meth:`~music21.base.Music21Object.wrapWeakref`, :meth:`~music21.base.Music21Object.write`

        Methods inherited from :class:`~music21.base.JSONSerializer`: :meth:`~music21.base.JSONSerializer.jsonAttributes`, :meth:`~music21.base.JSONSerializer.jsonComponentFactory`, :meth:`~music21.base.JSONSerializer.jsonPrint`, :meth:`~music21.base.JSONSerializer.jsonRead`, :meth:`~music21.base.JSONSerializer.jsonWrite`


ChromaticInterval
-----------------

Inherits from: :class:`~music21.base.Music21Object`, :class:`~music21.base.JSONSerializer`

.. class:: ChromaticInterval(value=0)

    Chromatic interval class. Unlike a Diatonic interval, this Interval class treats interval spaces in half-steps.  So Major 3rd and Diminished 4th are the same 

    Two ChromaticIntervals are equal if their size and direction are equal. 

    

    >>> from music21 import *
    >>> aInterval = interval.ChromaticInterval(-14)
    >>> aInterval.semitones
    -14 
    >>> aInterval.undirected
    14 
    >>> aInterval.mod12
    10 
    >>> aInterval.intervalClass
    2 
    >>> aInterval.isChromaticStep
    False 
    >>> aInterval.isStep
    False 
    >>> aInterval = interval.ChromaticInterval(1)
    >>> aInterval.isChromaticStep
    True 
    >>> aInterval.isStep
    True 

    **ChromaticInterval** **attributes**

        Attributes without Documentation: `directed`, `direction`, `undirected`, `isChromaticStep`, `cents`, `simpleDirected`, `isStep`, `simpleUndirected`, `mod12`, `semitones`, `intervalClass`

        Attributes inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.classSortOrder`, :attr:`~music21.base.Music21Object.hideObjectOnPrint`, :attr:`~music21.base.Music21Object.id`, :attr:`~music21.base.Music21Object.groups`

    **ChromaticInterval** **properties**

        Properties inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.activeSite`, :attr:`~music21.base.Music21Object.beat`, :attr:`~music21.base.Music21Object.beatDuration`, :attr:`~music21.base.Music21Object.beatStr`, :attr:`~music21.base.Music21Object.beatStrength`, :attr:`~music21.base.Music21Object.classes`, :attr:`~music21.base.Music21Object.derivationHierarchy`, :attr:`~music21.base.Music21Object.duration`, :attr:`~music21.base.Music21Object.measureNumber`, :attr:`~music21.base.Music21Object.offset`, :attr:`~music21.base.Music21Object.priority`

        Properties inherited from :class:`~music21.base.JSONSerializer`: :attr:`~music21.base.JSONSerializer.json`

    **ChromaticInterval** **methods**

        .. method:: getDiatonic()

            Given a Chromatic interval, return a Diatonic interval object of the same size. While there is more than one Generic Interval for any given chromatic interval, this is needed to to permit easy chromatic specification of Interval objects.  No augmented or diminished intervals are returned except for for interval of 6 which returns a diminished fifth, not augmented fourth. 

            >>> from music21 import *
            >>> aInterval = interval.ChromaticInterval(5)
            >>> aInterval.getDiatonic()
            <music21.interval.DiatonicInterval P4> 
            >>> aInterval = interval.ChromaticInterval(6)
            >>> aInterval.getDiatonic()
            <music21.interval.DiatonicInterval d5> 
            >>> aInterval = interval.ChromaticInterval(7)
            >>> aInterval.getDiatonic()
            <music21.interval.DiatonicInterval P5> 
            >>> aInterval = interval.ChromaticInterval(11)
            >>> aInterval.getDiatonic()
            <music21.interval.DiatonicInterval M7> 

            

        .. method:: reverse()

            Return an inverted interval, that is, reversing the direction. 

            >>> from music21 import *
            >>> aInterval = interval.ChromaticInterval(-14)
            >>> aInterval.reverse()
            <music21.interval.ChromaticInterval 14> 
            >>> aInterval = interval.ChromaticInterval(3)
            >>> aInterval.reverse()
            <music21.interval.ChromaticInterval -3> 

        Methods inherited from :class:`~music21.base.Music21Object`: :meth:`~music21.base.Music21Object.searchParentByAttr`, :meth:`~music21.base.Music21Object.getContextAttr`, :meth:`~music21.base.Music21Object.setContextAttr`, :meth:`~music21.base.Music21Object.addContext`, :meth:`~music21.base.Music21Object.addLocation`, :meth:`~music21.base.Music21Object.addLocationAndActiveSite`, :meth:`~music21.base.Music21Object.freezeIds`, :meth:`~music21.base.Music21Object.getAllContextsByClass`, :meth:`~music21.base.Music21Object.getCommonSiteIds`, :meth:`~music21.base.Music21Object.getCommonSites`, :meth:`~music21.base.Music21Object.getContextByClass`, :meth:`~music21.base.Music21Object.getOffsetBySite`, :meth:`~music21.base.Music21Object.getSiteIds`, :meth:`~music21.base.Music21Object.getSites`, :meth:`~music21.base.Music21Object.getSpannerSites`, :meth:`~music21.base.Music21Object.hasContext`, :meth:`~music21.base.Music21Object.mergeAttributes`, :meth:`~music21.base.Music21Object.purgeLocations`, :meth:`~music21.base.Music21Object.removeLocationBySite`, :meth:`~music21.base.Music21Object.removeLocationBySiteId`, :meth:`~music21.base.Music21Object.setOffsetBySite`, :meth:`~music21.base.Music21Object.show`, :meth:`~music21.base.Music21Object.splitAtDurations`, :meth:`~music21.base.Music21Object.splitAtQuarterLength`, :meth:`~music21.base.Music21Object.splitByQuarterLengths`, :meth:`~music21.base.Music21Object.unfreezeIds`, :meth:`~music21.base.Music21Object.unwrapWeakref`, :meth:`~music21.base.Music21Object.wrapWeakref`, :meth:`~music21.base.Music21Object.write`

        Methods inherited from :class:`~music21.base.JSONSerializer`: :meth:`~music21.base.JSONSerializer.jsonAttributes`, :meth:`~music21.base.JSONSerializer.jsonComponentFactory`, :meth:`~music21.base.JSONSerializer.jsonPrint`, :meth:`~music21.base.JSONSerializer.jsonRead`, :meth:`~music21.base.JSONSerializer.jsonWrite`


DiatonicInterval
----------------

Inherits from: :class:`~music21.base.Music21Object`, :class:`~music21.base.JSONSerializer`

.. class:: DiatonicInterval(specifier=P, generic=1)

    A class representing a diatonic interval. Two required arguments are a `specifier` (such as perfect, major, or minor) and a `generic`, an interval size (such as 2, 2nd, or second). 

    A DiatonicInterval contains and encapsulates a :class:`~music21.interval.GenericInterval` 

    Two DiatonicIntervals are the same if their GenericIntervals are the same and their specifiers are the same. 

    

    The `specifier` is an integer or string specifying a value in the `prefixSpecs` and `niceSpecNames` lists. The `generic` is an integer or GenericInterval instance. 

    >>> from music21 import *
    >>> aInterval = interval.DiatonicInterval(1, 1)
    >>> aInterval.simpleName
    'P1' 
    >>> aInterval = interval.DiatonicInterval('p', 1)
    >>> aInterval.simpleName
    'P1' 
    >>> aInterval = interval.DiatonicInterval('major', 3)
    >>> aInterval.simpleName
    'M3' 
    >>> aInterval.niceName
    'Major Third' 
    >>> aInterval.semiSimpleName
    'M3' 
    >>> aInterval.directedSimpleName
    'M3' 
    >>> aInterval.invertedOrderedSpecifier
    'm' 
    >>> aInterval.mod7
    'M3' 
    >>> aInterval = interval.DiatonicInterval('major', 'third')
    >>> aInterval.niceName
    'Major Third' 
    >>> aInterval = interval.DiatonicInterval('perfect', 'octave')
    >>> aInterval.niceName
    'Perfect Octave' 
    >>> aInterval = interval.DiatonicInterval('minor', 10)
    >>> aInterval.mod7
    'm3' 
    >>> aInterval.isDiatonicStep
    False 
    >>> aInterval.isStep
    False 
    >>> aInterval = interval.DiatonicInterval('major', 2)
    >>> aInterval.isDiatonicStep
    True 
    >>> aInterval.isStep
    True 

    

    **DiatonicInterval** **attributes**

        .. attribute:: directedName

            The name of the interval in abbreviated form with direction. 

        .. attribute:: directedNiceName

            The name of the interval in full form with direction. 

        .. attribute:: niceName

            The name of the interval in full form. 

        .. attribute:: generic

            A GenericInterval is an interval such as Third, Seventh, Octave, or Tenth. Constructor takes an integer or string specifying the interval and direction. The interval is not specified in half-steps, but in numeric values derived from interval names: a Third is 3; a Seventh is 7, etc. String values for interval names ('3rd' or 'third') are accepted. staffDistance: the number of lines or spaces apart, eg: E.g. C4 to C4 = 0;  C4 to D4 = 1;  C4 to B3 = -1 Two generic intervals are the equal if their size and direction are the same. 

            

        .. attribute:: name

            The name of the interval in abbreviated form without direction. 

        Attributes without Documentation: `specifier`, `isDiatonicStep`, `mod7`, `mod7inversion`, `simpleName`, `semiSimpleName`, `simpleNiceName`, `semiSimpleNiceName`, `directedSimpleName`, `specificName`, `directedSimpleNiceName`, `invertedOrderedSpecifier`, `prefectable`, `isStep`, `orderedSpecifierIndex`, `invertedOrderedSpecIndex`

        Attributes inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.classSortOrder`, :attr:`~music21.base.Music21Object.hideObjectOnPrint`, :attr:`~music21.base.Music21Object.id`, :attr:`~music21.base.Music21Object.groups`

    **DiatonicInterval** **properties**

        Properties inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.activeSite`, :attr:`~music21.base.Music21Object.beat`, :attr:`~music21.base.Music21Object.beatDuration`, :attr:`~music21.base.Music21Object.beatStr`, :attr:`~music21.base.Music21Object.beatStrength`, :attr:`~music21.base.Music21Object.classes`, :attr:`~music21.base.Music21Object.derivationHierarchy`, :attr:`~music21.base.Music21Object.duration`, :attr:`~music21.base.Music21Object.measureNumber`, :attr:`~music21.base.Music21Object.offset`, :attr:`~music21.base.Music21Object.priority`

        Properties inherited from :class:`~music21.base.JSONSerializer`: :attr:`~music21.base.JSONSerializer.json`

    **DiatonicInterval** **methods**

        .. method:: getChromatic()

            Return a :class:`music21.interval.ChromaticInterval` based on the size of this Interval. 

            >>> from music21 import *
            >>> aInterval = interval.DiatonicInterval('major', 'third')
            >>> aInterval.niceName
            'Major Third' 
            >>> aInterval.getChromatic()
            <music21.interval.ChromaticInterval 4> 

            
            >>> aInterval = interval.DiatonicInterval('augmented', -5)
            >>> aInterval.niceName
            'Augmented Fifth' 
            >>> aInterval.getChromatic()
            <music21.interval.ChromaticInterval -8> 
            >>> aInterval = interval.DiatonicInterval('minor', 'second')
            >>> aInterval.niceName
            'Minor Second' 
            >>> aInterval.getChromatic()
            <music21.interval.ChromaticInterval 1> 

            

        .. method:: reverse()

            Return a DiatonicInterval that is an inversion of this Interval. 

            >>> from music21 import *
            >>> aInterval = interval.DiatonicInterval('major', 3)
            >>> aInterval.reverse().directedName
            'M-3' 
            >>> aInterval = interval.DiatonicInterval('augmented', 5)
            >>> aInterval.reverse().directedName
            'A-5' 

        Methods inherited from :class:`~music21.base.Music21Object`: :meth:`~music21.base.Music21Object.searchParentByAttr`, :meth:`~music21.base.Music21Object.getContextAttr`, :meth:`~music21.base.Music21Object.setContextAttr`, :meth:`~music21.base.Music21Object.addContext`, :meth:`~music21.base.Music21Object.addLocation`, :meth:`~music21.base.Music21Object.addLocationAndActiveSite`, :meth:`~music21.base.Music21Object.freezeIds`, :meth:`~music21.base.Music21Object.getAllContextsByClass`, :meth:`~music21.base.Music21Object.getCommonSiteIds`, :meth:`~music21.base.Music21Object.getCommonSites`, :meth:`~music21.base.Music21Object.getContextByClass`, :meth:`~music21.base.Music21Object.getOffsetBySite`, :meth:`~music21.base.Music21Object.getSiteIds`, :meth:`~music21.base.Music21Object.getSites`, :meth:`~music21.base.Music21Object.getSpannerSites`, :meth:`~music21.base.Music21Object.hasContext`, :meth:`~music21.base.Music21Object.mergeAttributes`, :meth:`~music21.base.Music21Object.purgeLocations`, :meth:`~music21.base.Music21Object.removeLocationBySite`, :meth:`~music21.base.Music21Object.removeLocationBySiteId`, :meth:`~music21.base.Music21Object.setOffsetBySite`, :meth:`~music21.base.Music21Object.show`, :meth:`~music21.base.Music21Object.splitAtDurations`, :meth:`~music21.base.Music21Object.splitAtQuarterLength`, :meth:`~music21.base.Music21Object.splitByQuarterLengths`, :meth:`~music21.base.Music21Object.unfreezeIds`, :meth:`~music21.base.Music21Object.unwrapWeakref`, :meth:`~music21.base.Music21Object.wrapWeakref`, :meth:`~music21.base.Music21Object.write`

        Methods inherited from :class:`~music21.base.JSONSerializer`: :meth:`~music21.base.JSONSerializer.jsonAttributes`, :meth:`~music21.base.JSONSerializer.jsonComponentFactory`, :meth:`~music21.base.JSONSerializer.jsonPrint`, :meth:`~music21.base.JSONSerializer.jsonRead`, :meth:`~music21.base.JSONSerializer.jsonWrite`


GenericInterval
---------------

Inherits from: :class:`~music21.base.Music21Object`, :class:`~music21.base.JSONSerializer`

.. class:: GenericInterval(value=unison)

    A GenericInterval is an interval such as Third, Seventh, Octave, or Tenth. Constructor takes an integer or string specifying the interval and direction. The interval is not specified in half-steps, but in numeric values derived from interval names: a Third is 3; a Seventh is 7, etc. String values for interval names ('3rd' or 'third') are accepted. staffDistance: the number of lines or spaces apart, eg: E.g. C4 to C4 = 0;  C4 to D4 = 1;  C4 to B3 = -1 Two generic intervals are the equal if their size and direction are the same. 

    

    

    >>> from music21 import *
    >>> aInterval = interval.GenericInterval(3)
    >>> aInterval.direction
    1 
    >>> aInterval.perfectable
    False 
    >>> aInterval.staffDistance
    2 
    >>> aInterval = interval.GenericInterval('Third')
    >>> aInterval.staffDistance
    2 
    >>> aInterval = interval.GenericInterval(-12)
    >>> aInterval.niceName
    'Twelfth' 
    >>> aInterval.perfectable
    True 
    >>> aInterval.staffDistance
    -11 
    >>> aInterval.mod7
    4 
    >>> bInterval = aInterval.complement()
    >>> bInterval.staffDistance
    3 
    >>> aInterval = interval.GenericInterval('descending twelfth')
    >>> aInterval.perfectable
    True 
    >>> aInterval.staffDistance
    -11 
    >>> aInterval = interval.GenericInterval(0)
    Traceback (most recent call last): 
    IntervalException: The Zeroth is not an interval 
    >>> aInterval = interval.GenericInterval(24)
    >>> aInterval.niceName
    '24' 
    >>> aInterval.isDiatonicStep
    False 
    >>> aInterval.isStep
    False 
    >>> aInterval = interval.GenericInterval(2)
    >>> aInterval.isDiatonicStep
    True 
    >>> aInterval.isStep
    True 

    

    **GenericInterval** **attributes**

        Attributes without Documentation: `simpleUndirected`, `octaves`, `niceName`, `semiSimpleUndirected`, `simpleDirected`, `isSkip`, `mod7`, `mod7inversion`, `simpleNiceName`, `semiSimpleNiceName`, `undirected`, `isDiatonicStep`, `direction`, `perfectable`, `undirectedOctaves`, `directed`, `staffDistance`, `value`, `semiSimpleDirected`, `isStep`

        Attributes inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.classSortOrder`, :attr:`~music21.base.Music21Object.hideObjectOnPrint`, :attr:`~music21.base.Music21Object.id`, :attr:`~music21.base.Music21Object.groups`

    **GenericInterval** **properties**

        Properties inherited from :class:`~music21.base.Music21Object`: :attr:`~music21.base.Music21Object.activeSite`, :attr:`~music21.base.Music21Object.beat`, :attr:`~music21.base.Music21Object.beatDuration`, :attr:`~music21.base.Music21Object.beatStr`, :attr:`~music21.base.Music21Object.beatStrength`, :attr:`~music21.base.Music21Object.classes`, :attr:`~music21.base.Music21Object.derivationHierarchy`, :attr:`~music21.base.Music21Object.duration`, :attr:`~music21.base.Music21Object.measureNumber`, :attr:`~music21.base.Music21Object.offset`, :attr:`~music21.base.Music21Object.priority`

        Properties inherited from :class:`~music21.base.JSONSerializer`: :attr:`~music21.base.JSONSerializer.json`

    **GenericInterval** **methods**

        .. method:: complement()

            Returns a new GenericInterval object where descending 3rds are 6ths, etc. 

            >>> from music21 import *
            >>> aInterval = interval.GenericInterval('Third')
            >>> aInterval.complement()
            <music21.interval.GenericInterval 6> 

        .. method:: getDiatonic(specifier)

            Given a specifier, return a :class:`~music21.interval.DiatonicInterval` object. Specifier should be provided as a string name, such as 'dd', 'M', or 'perfect'. 

            >>> from music21 import *
            >>> aInterval = interval.GenericInterval('Third')
            >>> aInterval.getDiatonic('major')
            <music21.interval.DiatonicInterval M3> 
            >>> aInterval.getDiatonic('minor')
            <music21.interval.DiatonicInterval m3> 
            >>> aInterval.getDiatonic('d')
            <music21.interval.DiatonicInterval d3> 
            >>> aInterval.getDiatonic('a')
            <music21.interval.DiatonicInterval A3> 
            >>> aInterval.getDiatonic(2)
            <music21.interval.DiatonicInterval M3> 
            >>> bInterval = interval.GenericInterval('fifth')
            >>> bInterval.getDiatonic('perfect')
            <music21.interval.DiatonicInterval P5> 

        .. method:: reverse()

            Returns a new GenericInterval object that is inverted. 

            >>> from music21 import *
            >>> aInterval = interval.GenericInterval('Third')
            >>> aInterval.reverse()
            <music21.interval.GenericInterval -3> 
            >>> aInterval = interval.GenericInterval(-13)
            >>> aInterval.direction
            -1 
            >>> aInterval.reverse()
            <music21.interval.GenericInterval 13> 

            
            Unisons invert to unisons 

            
            >>> aInterval = interval.GenericInterval(1)
            >>> aInterval.reverse()
            <music21.interval.GenericInterval 1> 

        Methods inherited from :class:`~music21.base.Music21Object`: :meth:`~music21.base.Music21Object.searchParentByAttr`, :meth:`~music21.base.Music21Object.getContextAttr`, :meth:`~music21.base.Music21Object.setContextAttr`, :meth:`~music21.base.Music21Object.addContext`, :meth:`~music21.base.Music21Object.addLocation`, :meth:`~music21.base.Music21Object.addLocationAndActiveSite`, :meth:`~music21.base.Music21Object.freezeIds`, :meth:`~music21.base.Music21Object.getAllContextsByClass`, :meth:`~music21.base.Music21Object.getCommonSiteIds`, :meth:`~music21.base.Music21Object.getCommonSites`, :meth:`~music21.base.Music21Object.getContextByClass`, :meth:`~music21.base.Music21Object.getOffsetBySite`, :meth:`~music21.base.Music21Object.getSiteIds`, :meth:`~music21.base.Music21Object.getSites`, :meth:`~music21.base.Music21Object.getSpannerSites`, :meth:`~music21.base.Music21Object.hasContext`, :meth:`~music21.base.Music21Object.mergeAttributes`, :meth:`~music21.base.Music21Object.purgeLocations`, :meth:`~music21.base.Music21Object.removeLocationBySite`, :meth:`~music21.base.Music21Object.removeLocationBySiteId`, :meth:`~music21.base.Music21Object.setOffsetBySite`, :meth:`~music21.base.Music21Object.show`, :meth:`~music21.base.Music21Object.splitAtDurations`, :meth:`~music21.base.Music21Object.splitAtQuarterLength`, :meth:`~music21.base.Music21Object.splitByQuarterLengths`, :meth:`~music21.base.Music21Object.unfreezeIds`, :meth:`~music21.base.Music21Object.unwrapWeakref`, :meth:`~music21.base.Music21Object.wrapWeakref`, :meth:`~music21.base.Music21Object.write`

        Methods inherited from :class:`~music21.base.JSONSerializer`: :meth:`~music21.base.JSONSerializer.jsonAttributes`, :meth:`~music21.base.JSONSerializer.jsonComponentFactory`, :meth:`~music21.base.JSONSerializer.jsonPrint`, :meth:`~music21.base.JSONSerializer.jsonRead`, :meth:`~music21.base.JSONSerializer.jsonWrite`


