“Online services account for just a small fraction of overall music sales, but they’re growing rapidly. And the new choices they give consumers threaten to remix the recording industry’s traditional revenue streams, pumping up the volume of singles and subscriptions and turning down album sales. The shift to online shopping could be lucrative for the music industry if the flexibility and convenience lead people to spend more on tunes than they do today. But some industry executives and analysts fear the opposite result, with music lovers buying a few 99-cent singles instead of $15 CDs.”