Gnoosic - Even if you don't know what you are looking for - gnod will find it.
Songlink - Share music with anyone.
Musicroamer - A visual Pandora for discovering new music
humit - A social networking app for music sharing and discovery.
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.
aux.app - A free web-based music platform to play music from other popular online streaming services.