Spinning the radio dials like mini roulette wheels was, in 1993, the best way to discover new music. Static, a snatch of a familiar song, a news report, then ah wait that sounds interesting. You’d walk into a record store with that song stuck in your head, and with any luck would walk out after a conversation with the clerk a few tapes richer, a few dozen dollars poorer.One year later, everything had changed. For in 1994, the best way to discover new music was to email an AI.“This sounds ****in’...