BOSTON-To a fan of the Louisville-based band My Morning Jacket, the release of their most recent album, Z (2005), represented a new direction. The band seemed to be shedding its sound-a dogged, effervescent, country-tinged rock 'n' roll power play-in favor of an edgier, more experimental sound that pushed the boundaries of the rock genre on several fronts, bleeding over into jazz, punk and even reggae. The rock- steady rhythms, slow and evocative pedal-steel guitar and simple song structures-everything that fans of the younger My Morning Jacket found so attractive-were replaced by something more closely resembling progressive rock. "We are the innovators!" sang lead singer and frontman Jim. Considering the band's reputation for putting on incredible live shows, the question arose as to whether the band would continue its tradition of high-powered classic southern rock in concert, or abandon that course for a new live sound, as well.

Playing to a maximum-capacity audience at The Avalon Saturday night, the quintet settled that question, showing it can still rock a crowd the same as ever, even with some new material integrated into the set list. From the evening's beginning-the relentless drum roll that opens the fan-favorite anthem "One Big Holiday"-the mood was pure, unadulterated rock with no frills, no long drawn-out jams, no avant-garde pretense and no nonsense. Except during the occasional acoustic number, this mood carried over through the whole evening, with each number unraveling into a simply-structured combination of charging chords, powerfully reverberating vocals and thunderous drumbeats.

While much of Z was performed, an overwhelming amount of the material came from earlier albums-notably It Still Moves, which, while certainly not the band's most commercially successful album, is often considered their best. Each song was more or less played exactly as it sounded on record, indicating an intention on the part of the band to play its music in the most familiar of ways, rather than reinterpreting old material through the prism of its more recent, exploratory sound.

To some, this hold-to-your-roots attitude might equal an artistic cowardice which will inevitably prevent My Morning Jacket from ever achieving greatness. But, after watching them play in concert, I'm more inclined to believe the band has already produced a share of timeless music, and it would be wrong to expect a yield of anything much greater if it continues drifting from its original sound. My Morning Jacket's strong point, after all, is its ability to play gritty dance rock-something handed down from one band to another through the decades following the birth of that particular style of American music over 50 years ago-and not its tentative trials at experimentation. Furthermore, it's clear that, despite the band's recent detours, it recognizes these strengths.

If Saturday night's concert was any indication, Jim James' claim that My Morning Jacket are "the innovators" rings hollow. This is a band that, instead of pushing its frontiers to stake out new territory, bears the equally (if not more) important task of carrying the torch of tradition through this decade.