Combining tribal African polyrhythms with energetic funk grooves, Boston's premier afrobeat group, The Superpowers, brought last Saturday's crowd at Regattabar Jazz Club to a dancing pandemonium. The Superpowers are a self-described "11 member, 21st Century Dance Band," and a dance band they are indeed.Arriving at the show 20 minutes early to ensure a decent seat, I was overwhelmed by the dense crowd of avid fans and, hilariously, the band members' parents. Much to my disappointment and especially to the parents', the show was sold out to what seemed like mostly stiff older white couples looking to do something novel, like go to a jazz club. But Saturday's show was not "just an ordinary jazz show," the angry mob of parents protested. The hosts' fortitude waned, and the rush of parents toppled the flood gates, seemingly displacing the small minority of youngsters who had actually made it to the show in time to get proper seats. The rest of the thoroughly amused but antsy group of approximately 40 young college kids, Bostonian hipsters and a solitary wholesome family of three (wife, husband and toddler boy) settled for the standing room in the back.

We standers were at first perturbed by this inconvenience, and the toddler had trouble seeing over the towering "big kids and grown-ups," but we were quickly taken by the music. There was initially the apprehensive tap of the foot, then an oscillation of the knees, next the hips gave way, followed by loosely rotated elbows, and finally all of the bodies gyrated wildly. Out of the corner of my eye, I spotted a few perplexed glares from the curmudgeonly sitters. It didn't matter to us though-the music had entered our veins.

At the core of The Superpowers' gripping vibe was the multilayered percussion section. Led by drummer Adam Clark, three main percussionists blended together beats with independent time signatures, mimicking the call-and-response effect of traditional West African drum circles. Clark's lead drumming held the band together, and the underlying varied rhythm gave the music a sense of continual urgency. Ordinarily, we associate color with particular harmonies and melodies, but the synergy of The Superpowers' percussion added an intense hue by way of polyrhythms alone. At times members of the four-piece horn section would lay down their instruments to join on hand drums in a spasmodic explosion.

Below the horns' sweeping melodies, two guitarists established a typical funk riff and single chord change at the beginning of each song, with electric keyboard providing an ambient harmony to establish the correct mood. The horn section, which consisted of tenor and alto sax, trumpet and trombone, played triumphantly loud repeated melodies over which a soloist would improvise. Although the horns were repetitious, the band's rhythmic complexity and variation of dynamics kept songs interesting and stimulating. The horns were not an annoyance because the other parts of the band subtly lead the listener's imagination to sweep across vast open plains, dipping down briefly into a pond of water and then back up, soaring into the sky. The guitar and keyboard riffage faded in and out, the bass chose only to play on certain beats, and the charged percussion players beat onwards. All the while, three of the horns played a repeated line while the fourth soloed. Especially exciting was Nick Videen's six-minute tenor saxophone solo on "Abbey Rockers 2."

Sensory highlights included a song titled "Acid Rain," which vividly painted rejoicing villagers, united and in motion. But from such subtle and eventual tinkering in the melody combined with a guitar riff played in a lower register, a corrupting texture crept up upon the villagers, bringing filth and ugliness. The song was not depressing or lethargic; rather, the crowd was inspired to dance passionately.

As the show became more intense, the dancing latecomers made their way to the front and convulsed in harmony with the swaying horn players. These adventurous audience members helped the band engage the rest of the concertgoers in clapping a layered rhythm for the introduction of "Color Blind," which featured two separate melodic sections, the first a dark and dissonant entrancing melody and the second a cathartic release of a soothing two-chord change.

By the end of the show, the once serious connoisseurs of culture's higher novelties had become light hearted and successfully completed at least a dozen foot taps that landed on the beat. The rest of us were sweaty, rejuvenated and sure that we were the most youthful crowd ever to turn Regattabar into a "21st Century Dance Floor."

The Superpowers can be heard on their Myspace at http://myspace.com/thesuperpowers. Regattabar is located in the Charles Hotel in Harvard Square. Coming up Feb. 8 and 9 is blues player extraordinaire Dr. John.