Jamstix - Advanced virtual drummer featuring real-time modeling of various drum styles.
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
NodeBeat - Make music with NodeBeat, the intuitive and fun visual music app for all ages.
Krue - Twitch for music: live streams from amazing musicians
GarageBand - GarageBand is a fully equipped music creation studio for Mac
Soundscape - Sync your music with the open source community