Spotify - Map shows when two people play same song at same time
Amper Music - Artificial intelligence music composer
Last.fm - The world's largest online music service. Listen online, find out more about your favourite artists, and get music recommendations, only at Last.fm
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
SoundCloud - Enjoy music & follow favourite artists
WaveBots Editor - Procedural music and sound maker that exports to Wav, MIDI, GoatTracker and much more.