Featured Activity: http://www.poissonrouge.com/choir/ A nifty little choir tool!

http://trainer.thetamusic.com/en Music games and tools

Whack a note: http://artsedge.kennedy-center.org/interactives/steprightup/whackanote/index.html

Giant catalogue of music sites and apps: http://cybraryman.com/music.html#other

http://www.themusicinteractive.com/TMI/Download.html a huge list of free (and paid) downloads

http://musescore.org/ Free music composition and notation software

http://www.jewelbeat.com/ Free music and sound effects (copyright free)

http://www.incredibox.fr/ A really nifty, cool music creator tool - fun!

http://livebinders.com/play/play_or_edit?id=32113 A great collection of music resources!

http://handsonlycpr.org/symphony/ An awesome, quick composition tool that uses the sounds of hands. You can even email your composition to someone.

http://www.fiddleafriend.com/ Compose lyrics for a beaver on a fiddle - yes, a weird concept but fun! (select type of music first - rh side, then type in lyrics, add a photo and preview)

The Blues Maker: http://www.thebluesmaker.com/

A fun dice Minuet maker:
http://sunsite.univie.ac.at/Mozart/dice/