MUSIC PLAYER | How to set up your music library | Steam | TUTORIAL
You can adjust other options from this window, too. For example, you can have Steam automatically pause music when you start an application, and control whether it’s automatically paused while you’re voice chatting within Steam. You can also choose whether you want to see a notification when the track changes.
Play Music From the Desktop
To view your music library, you can visit the “Library” tab in Steam, click the label at the right side of your search box, and select “Music” to view your music library instead of your game library. You can also just click View - Music details to view your music library.
If you have some games that include soundtracks installed, you might see some music here even if you haven’t provided any of your own music yet.
Start playing music back from your library and the music player will appear. You can also select View - Music player to open it.
Of course, this feature is particularly useful because you can control music playback from within games without Alt+Tabbing.