This 6-CD set captures Phish in the midst of a period of great growth. Across two visits to St. Louis’ American Theater—one in April of 1993 and the other four months later—the band is displayed here as a musically tight, endearingly ambitious unit whose creativity is gaining steady force and is almost ready to burst the dam. Phish was growing exponentially at the time, both as a creative force and a commercial one. The year before, the band played two shows at a brick box of a club in St. Louis called Mississippi Nights. For this visit, Phish had graduated to an august Beaux-Arts-style theater with twice the seating capacity. The two shows here are best heard straight through, as the band shows itself in fighting trim and bursting with energy. Try the door-slammer of a “Runaway Jim” from April 14, which sounds powered by rocket fuel, or the explosive “Axilla” show opener from August 16, during which each band member sounds like he’s out for blood. That August show is not an obvious pick from a summer tour in which Phish did much to outline the aesthetic that would mark its finest years. You can hear the group not quite breaking through into the improvisational heights it would reach the next year, but nevertheless straining at the boundaries of song form. “Possum” features advanced experiments in tension and release, repeatedly caving in on itself only to explode back into full force as Trey Anastasio spews flurries of 16th notes. Both “Mike’s Song” and a thrilling “Weekapaug Groove” feature unusually open jams, even if neither fully expands into one of the fragmented song suites for which this summer tour is best remembered. St. Louis ‘93 is the sound of a young band on the hunt, closing quickly behind the big game on the horizon.