You are ignoring the fact that digital music is cheaper.
At 99 cents a song people don't have to pay $20 for an album in which they want 3 songs.
Also the 1990's were a music bubble fueled by things like MTV. Music sales are consistant with the decades before. It had nothing to do with piracy and everything to do with a bubble and people having more control over what they want via things like itunes.








