Online music services are growing ever-more important as tools to find new music, though radio continues to lead the pack.

The NPD Group reveals that in March 2005 approximately 77.2 million customers listened to music on a computer, up 22 per cent year-on-year.

Online radio stations also saw growth, with 53.5 million listeners, 8.2 million more than a year ago. Traditional radio saw listening audiences shrink 4 per cent, the US report said.

NPD music and movies division president Russ Crupnick told Cnet "The rise of digital listening and storage for music continues unabated this year. Technology companies are providing new tools to consumers in the form of powerful music-enabled PCs and portable music players; music companies are answering the call for more content; and consumers are responding positively."

Additional statistics bear out these claims: 127 per cent more users transferred music to portable devices than last year, and the number of people ripping music to their computers has also doubled, while the rate of digital download sales continues to accelerate.