Music21: a python toolkit for computer-aided musicology

more music libraries or languages:

JFugue: http://www.jfugue.org/

mingus: http://code.google.com/p/mingus/

OpenMusic: http://en.wikipedia.org/wiki/OpenMusic

Strasheela: http://strasheela.sourceforge.net/strasheela/doc/index.html

Common Music: http://commonmusic.sourceforge.net/

other "music programming languages": http://www.nosuch.com/plum/cgi/showlist.cgi?sort=name&co...