Here are a few pieces of music entirely composed in µO.
The following are direct recordings of VST instruments rendering a real-time MIDI output stream from µO:
Tout va bien (merci)
Download the ready-to-go 357 image archive, unzip it anywhere and start
That's it; you don't need the following instructions.
squeak.exe: you will see the Squeak window.
muO.***.sarfile, and start again from a new copy of the base folder.
muO.***.sarpackage are available on SqueakMap.