The cheap seats had it all over the house seats at Wolf Trap on Friday night when boogie king John Lee Hooker performed. While folks out on the lawn had little more to contend with than damp ground, a lot of people inside the Filene Center found themselves caught in a sudden downpour during the intermission when the sprinkler system malfunctioned and drenched the aisles and adjoining seats on both sides of the facility.

The 10-minute shower and subsequent delay, however, didn't severely dampen the crowd's spirits. By then, John Mayall and the Bluesbreakers had already won the audience over, with a lean, punchy set that focused primarily on songs from the band's last two albums, topped off by an invigorating reprise of Mayall's trademark harmonica romp, "Room to Move." Twelve-bar blues dominated the show, but the shifting tempos allowed guitarist Coco Montoya to fashion a series of both subtly expressive and stinging solos, and Mayall to prove that he hasn't lost his enthusiasm for performing. Former Bonnie Raitt bassist Freebo helped anchor the quartet.

Given the unexpected shower during intermission, one half expected Hooker to come out singing his tale of a flood, "Tupelo." Instead, the 72-year-old blues legend took his seat in front of a seven-piece sax- and harmonica-driven ensemble, cradled his guitar in his lap, and -- in a sometimes world-weary, sometimes defiant, always imposing rumble of a voice -- sang several other classics, including the brooding "Serves You Right to Suffer," a juggernaut-like "Boom Boom Boom Boom" and a decidedly lascivious "Crawling King Snake." For all his band's firepower, the tone of the show was set by Hooker's elemental guitar playing as much as anything else, particularly his thumping boogie patterns and spooky hammer-ons and pull-offs; near the end of the show he roamed the stage and even choreographed the boogie tunes with some slow grinding hip motion.