jMusic is a project designed to provide composers and software developers with
a library of compositional and audio processing tools. It provides a solid
framework for computer-assisted composition in Java, and is also used for
generative music, instrument building, interactive performance, and music
analysis. jMusic supports musicians with its familiar music data structure
based upon note/sound events, and provides methods for organising,
manipulating and analysing that musical data. jMusic scores can be rendered as
MIDI or audio files for storage and later processing or playback in real-time.
jMusic can read and write MIDI files, audio files, XML files, and its own .jm
files; there is real-time support for JavaSound, QuickTime and MIDIShare.
jMusic is designed to be extendible, encouraging you to build upon its
functionality by programming in Java to create your own musical compositions,
tools, and instruments. In a spirit of mutual collaboration, jMusic is
provided free and is an open source project.

WWW: http://explodingart.com/jmusic/