The Economist has a good article up about the decline of the recording industry: The music industry from major to minor.
It won’t tell you anything you don’t already know ifyou’ve been following this sage, but it is a good summary.
(Note that I call it the “recording industry” rather than the “music industry” because there are lots of economic activities about music: for example manufacturing, distributing and selling musical instruments, teaching people to play musical instruments, playing music in front of live audiences, being a venue for the above, making and selling clothing with images of bands on it, etc. These industries are not, as far as I am aware, in decline the way the recording indsutry is. Maybe that’s because these industries are based on making something people want whereas the rcording industry is based on rent-seeking.)