My column for this week’s Reader is on Legitmix, a Web-based music distribution service that when it launched seemed poised to accomplish something respectable but not exactly earth-shattering: make it easier for DJs to sell mixes that include copyrighted material by other artists. Recently it unveiled “Rush Over Bklyn,” an El-P remix of his own “Drones Over Bklyn” that replaces his original beat with big chunks of Rush’s “Tom Sawyer.” El-P made it without getting the band’s permission but by all available evidence did so in a way that doesn’t run afoul of intellectual property law.

While I was preparing to write the piece I spoke with Omid McDonald, the guy who came up with this deviously brilliant little piece of technology, which stands to change the whole way artists on both sides of the sampling divide deal with the issue. After the jump, the interview: