Slackbox - Spotify playlist collaboration through Slack
humit - A social networking app for music sharing and discovery.
Brain.fm - Music designed for the brain to enhance focus, relaxation, meditation, naps and sleep within 10 - 15 minutes of use.
Songlink - Share music with anyone.
SoundCloud - Enjoy music & follow favourite artists
Son.gg in Slack - Share music with your team in Slack