Some early tangible signs of that idea are now beginning to come to market, as the record companies start exploring ways to revitalize and protect their flagging CD business. For some time, occasional CDs have shown up with digital goodies like screensavers or links to secret Web sites included. Next month, taking the idea a little farther, Universal Music Group will release a handful of compact discs that include MP3 files specifically coded to let people play DJ on their computer, remixing and making digital playlists of songs.
