Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
AMPLI.FI - Live online music community. Twitch for tunes.
Turntable.fm - Turntable.fm is a social media website developed by Billy Chasen and Seth Goldstein that allows the audience to stream their own music.
Krue - Twitch for music: live streams from amazing musicians
indiesound - indiesound is a multi-tasking platform developed for online music streaming, helping you to discover, listen and connect with thousands of indie bands or music artists all around the world.
Soundscape - Sync your music with the open source community