WaveShop - Open source audio editor
Spotify - Map shows when two people play same song at same time
TwistedWave - TwistedWave is one of the unique audio editors that allow you to edit your music file online without any installation.
SoundCloud - Enjoy music & follow favourite artists
Audacity - Audacity is a free and open-source audio production software suite that includes a surprising array of editing tools and recording systems.
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