Tom Petty and the Heartbreakers will release their new single, "Free Girl Now," as a free downloadable MP3 file on "MP3.com" Monday (March 1). Major labels -- including Warner Bros., for which Petty records -- have largely shunned MP3s, claiming the easily copied, near-CD-quality format encourages unauthorized distribution of music. Petty and the Heartbreakers' album Echo hits stores April 13.