Spotify - Map shows when two people play same song at same time
SoundCloud - Enjoy music & follow favourite artists
SOUNDS - Discover music with friends
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
Songlink - Share music with anyone.
Pandora - Pandora Radio is a free (ad-supported) internet radio founded in 2000.