Orkut Applications

There are many applications you can add that allow you to play music on your profile, but as far as “background” music goes (I’m guessing you meant music that plays when some one clicks on your profile),Then this is not possible as Facebook and orkut differs from from other social networking sites like myspace, hi5 etc on this matter as they avoid playing bacground music automatically on users profiles.

Infact you can use some music  applications to add application like iLike, Boombox, and Profile Song, etc which is used by facebook users for listening latest music inside facebook.

• My Music - allows you (and your friends) to view and listen to your entire iTunes & WMP libraries any time you want and from any computer — including your recently played songs, created playlists, your top artists and much more!
• iLike - iLike lets you add music and videos to your profile, dedicate songs to your friends, and see who’s going to what concerts.
• Profile Song lets you add a single song to your Facebook profile. Let your friends easily hear which is your favorite song or upload your own. you can suggest songs to your friends and receive suggestions for songs they like the most.

Inspite of these there ore other many other popular music application that help in playinh music inside facebook profile .