No-one expected this. Previously, Mercury Rev had been the David Baker fronted psyche-noise outfit that was as likely to pick a fight with the audience than write a work of transcendent beauty. Records like Yerself is Steam and Boces are great fun, full of guitars that are distorted to the point where they cease being guitars, and crazy, stream of consciousness lyrics. But they certainly didn’t position the band as one of the most significant bands of the 90s, and this is exactly what Deserter’s Songs did. A couple of things had to happen in order for this change to take place, though. Baker was out,…