Apple Music Web App - Apple Music is now available to stream on the web
Spotify - Map shows when two people play same song at same time
Musish - A web client for Apple Music
SoundCloud - Enjoy music & follow favourite artists
Tempso - Finally a place for classical music online!
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