'THESE guys should play bigger venues,'' a woman to my left muttered into the sweaty air at the densely packed Habib Koite and Bamada show at the Iron Horse on Monday night. She was standing on her booth, I was standing on the club's stairs.

  The homey club was crowded to the rafters, with standing room only on the bottom floor and people dancing among the packed tables up in the loft-like second level. Weary table servers tirelessly tried to maneuver trays of drinks through the happy chaos, where all the usual aisles, boundaries, sightlines and free spaces were obliterated by people holding dearly to their hard-fought spot, craning their necks to see the band.

Of course Koite and Bamada do usually play larger rooms, but the closeness of the musicians to the audience (and the ''excuse me, I'm on top of you'' amount of space between audience members) made for a personal and memorable show. There were couples on dates, parents and their kids and everyone and their grandmother wedged up tight and dancing, smiling, cheering wildly at the ends of songs, and Koite smiled radiantly in return.

The joyful vibe swallowed up the usually uptight Iron Horse and turned the concert into a real party, where the full roar of a satisfied crowd further electrifies the air.

Koite and Bamada just released a new double live CD entitled ''Foly! Live Around the World,'' which features lengthy workouts of many of the Mali-based vocalist/guitarist's West African and European hits. The six-piece group treated the Northampton crowd to the same generous groove, playing a set of nine long songs (plus an encore).

The musicians were striking before they even played a note, dressed head to toe in beautiful clothing colored every shade of brown; all their instruments (except the shiny black drum set) were also brown, earthy, woody; visually Bamada were presented like a work of art.

Like any show it took band and audience a few songs to find the mood; for a while the floor was filled with cross-legged seated folks, and the concert had more of a studious atmosphere. Koite played an electric-acoustic guitar, fingerpicking beautifully (he used to teach the instrument and his skill is apparent).

By his side was fellow electro-acoustic guitarist Boubacar Sidibe, who also played harmonica. The rest of the band included master balafon player and violinist Keletigui Diabate, drummer Souleymane Ann, percussionist Mahamadou Kone, and bassist Abdoul Wahab Berthe.

The group had an amazingly clean sound, with the shimmering guitars supported by a hiccuping, percussive pulse of talking drum, balafon (wood xylophone), and a minimalist hi-hat/wood block/bass drum beat, while bassist Berthe played unobvious, accented lines that held it all together. The beginning of the set was unarguably rhythmic but surprisingly sober, full of minor chords and sedate tempos. There was a melancholy tinge to much of the music.

The atmosphere changed with the fourth song, as if the sun shone brighter, and much of the audience found its way to its now-moving feet. Even as it happened, it was impossible to figure out if the crowd stood because the groove opened up, or the other way around, but the result was that it all clicked. Koite and his band improvised more, stretching out the songs and engaging the audience in call-and-response shouts and even a handclapping game, dividing the room into two sections, each with its own clapping pattern to keep up against the other's.

Koite had to explain the game with exaggerated hand movements, as he spoke in somewhat stumbling and basic English. Besides the occasional ''thank you,'' Koite only talked to the crowd at length once, in the middle of the show, to mention the new live album, and to call special attention to balafon master Diabate, who he said brought ''power to the band with his age and experience.''

His deep respect for the 70-something Diabate was clear, but Koite did not let the seasoned multi-instrumentalist rest on any laurels. During one number on which Diabate played violin, he turned to face Diabate and forced him into a playful call-and-response duel between the guitar and his violin, making him go higher and higher up the violin's neck until they were both squeaking over the propulsive beat.

Koite's music was simple and hypnotic, yet it always surprised, encompassing traditional elements (one song featured the kamele ngoni and a wood flute, others found the frontline doing African dance movements) and bits of other styles like jazz and even a more modern-sounding aggressive rap while Ann and Berthe funked out in the rhythm section.

There was no downtime during the evening; as one song ended, Kone was already whipping up the next with a stirring rhythm on his talking drum. The audience had plenty to celebrate, and that included the audience outside. I left the club at one point to get some fresh air and some bundled-up folks had gathered on the chilly evening sidewalk, dancing gently near the glass separating them from the warm stage beyond. The music was muffled out here, but the energy and rhythm inside was too much for one vibrating building to keep to itself.