The sad part: this was another woefully underattended concert. The Atlas is a good venue, comparatively intimate for an auditorium setting, but Saturday night went beyond intimate. “Small crowd, huh?” Harper laughed. “Let’s hope y’all know how to clap loud and fast.”

Still, the sub-50-percent capacity did little to dampen the spirits of the group. Harper is luminous in a trio—his accompaniment hard and tight, his brushwork impressionistic and masterful—but thoroughly unleashed once the full sextet is onstage. With fireworks on the tom-toms, he punctuates his players’ solos in all the right places, challenging them to match him flourish for flourish, and in his hands, a standard like Bobby Timmons‘ “Moanin’” becomes something else entirely—as he barrels through the four-beat swing, his hands blurring before your eyes, you can’t help but feel that the song will never be the same.

On tenor sax, Dayna Stevens has the hoarse smokiness of a low-range Paul Desmond, and his interchange with Bruce Harris (trumpet) is funky, sensitive, and graceful. The other players—Jon Notar on piano, D.C. native Ameen Saleem on bass, and Jean-Marie Collatin on assorted percussion—form a tight unit with a slick, easy response to the histrionic virtuosity of their leader. Also nice: the full dynamic range, even when down-tempo (cf. “I’ve Never Been in Love Before”).

They wound down the set with “All Praise Is to God” (a Harper original), “Tamisha” (a Saleem original), a piano-led “Amazing Grace,” Ruben Brown’s “Float Like a Butterfly” (not a bad tagline for this combo, come to think of it), and a few others that escape the memory.  There wasn’t a doubter in the house. But the house, after all, was small.