Spotify - Map shows when two people play same song at same time
Clone Hero - Clone Hero is a free rhythm game, which can be played with any 5 or 6 button guitar controller...
SoundCloud - Enjoy music & follow favourite artists
Osu - Osu is Music, Rhythm, Single and Multiplayer video game developed by Dean Herbert.
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
StepMania - Rhythm game for Windows, Mac, and Linux.