http://media.steampowered.com/img/music/music_album.png
"The Steam Music Beta is coming soon to Big Picture and SteamOS interfaces, with desktop features soon to follow. To express interest in beta participation, join the Steam Music community group. Group members will be invited in waves, until the feature is released to everyone.

With Steam Music, you can now listen to your music collection while playing games. Once you’ve pointed Steam to your local music directory, your Steam Library will include Album and Artist views of your collection.
"

It seems Steam is getting the ability to play music in Big Picture mode and SteamOS. This should come as good news to people planning on using a Steam Machine as a Media Center. The interface is clean and I like that you can bring it up when you are playing a game.

http://steamcommunity.com/groups/steammusic#announcements/detail/1498873168009439000