Spotify - Map shows when two people play same song at same time
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
SoundCloud - Enjoy music & follow favourite artists
GNUitar - GNUitar is guitar effects software that allows you to use your PC as guitar processor.
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
Ampire - State Space Modeled guitar amp/cab/stompbox simulator.