STEAMp3

http://steamp3.ta0soft.com/

Is it legitimate? There not problems to be an external program?

It would be quite useful

"STEAMp3 is a revolutionary new media player designed for Steam. Including over 170 commands, achievements, skins, plug-ins and much more!

Listen to your favorite songs while you browse the web, talk to friends, and play games using the Steam integrated chat and private message commands. Share your music with friends and record live via Steam or in-game!

No music? No problem! STEAMp3 includes over 50 radio stations streaming live 24 hours a day. Add your own stations by linking to any .pls or .m3u file hosted on the web.

Earn achievements based on the songs you play and by using commands. The more achievements you earn, the higher your overall rank will be among other users.

Skins allow you to personalize the look and feel of STEAMp3. Choose from a long list of skins created by Ta0soft and users of the STEAMp3 community.

Microsoft Visual C# developers can create custom plug-ins using the STEAMp3 Development Kit (SDK) included with the setup and available on the Download page."