This is one of the best ways to discover music I have found. Their app for mobile phones is easily superior to any of it's relative competition. Super-easy to use and clean.
Excellent site musical, si ce n'est le meilleur pour les musiques électroniques, les meilleurs producteurs/dj's y sont présent et y officient avec fougue et talent. Un must les amis ;)
Soundcloud is using "Quantcast", "Adroll", "Comscore Beacon", and "Doubleclick" which are tracking technologies. But if you don't take a look at this point, this is the best website for music sharing.
This site is an excellent site for music producers to upload their music. It does, unfortunately have some copyright infringing music on it, but that is to be expected since anyone can upload to it.