Tempso - Finally a place for classical music online!
tonestro - Practice & improve on your wind instrument while having fun
musicForProgramming(); - Mixes intended for listening while programming
Piano2Notes - Piano2Notes is a web application and mobile that transcribes your piano tune into a digital word document.
Music-Map - The Music-Map is the Tourist Map of Music, part of Gnod, the Global Network of Discovery.
Melodics - Melodics is a desktop app that teaches you to play MIDI keyboards, pad controllers, and drums.