Find a music teacher, try writing your own music, and follow links to other great music sites! http://www.playmusic.org/
You can compose your own music and play with musical performance, games and puzzles. http://www.creatingmusic.com
Learn about instruments, create your own Rhythm Band http://www.sphinxkids.org
Interactive guide to the sypmphony orchestra, a tour or each instrument. Listen to the sound clips as your explore. http://library.thinkquest.org/22673/orchestra.html