The RIAA just put out the music industry’s midyear revenue report, and it’s a stark illustration of the haves / have-not divide that’s been accelerating in the streaming era. Actually, scratch that: it’s a terrific illustration of how good it is for the haves: retail revenue is up 9.3 percent to an all-time first half high of $8.4 billion, while wholesale revenue is up 8.3 percent to 5.3 billion. (You can read a good explanation of retail versus wholesale here; the industry focuses on retail ...