While most Americans know Kevin Eubanks for his 15 years as Jay Leno’s bandleader and sidekick, jazz devotees remember the guitarist’s straight-ahead bop and funky, world-music-imbued experiments from his pre-“Tonight Show” career. (Cory Schwartz/Getty Images)

While most Americans know Kevin Eubanks for his 15 years as Jay Leno’s bandleader and sidekick, jazz devotees remember the guitarist’s straight-ahead bop and funky, world-music-imbued experiments from his pre-“Tonight Show” career.

The audience that packed Blues Alley to see him Thursday night, however, got neither of the above. Armed only with saxophonist Bill Pierce and bassist Rene Camacho (longtime drummer Marvin “Smitty” Smith was nowhere to be found), Eubanks performed an evening of hypnotic jazz fusion.

Its hypnotic aspect came from its narrow spectrum of harmony. The set’s five pieces were all modal, built on long drones and repetitive vamps that didn’t much change as the tunes went on. That was to be expected from Miles Davis’s “All Blues,” one of the classics of modal jazz, but originals such as “The Dirty Monk” followed the same pattern. The latter was in a sinister minor key, with Eubanks’s fingerpicked chords emanating darkness without relief.

That’s not to say there was no variety in the show. Eubanks and Pierce made up for their harmonic sameness with constant changes of approach and texture. In “All Blues,” Pierce shifted gradually from stately, lyrical declarations to the unchecked cascades once dubbed “sheets of sound.” The closing “6/8” found him blowing riffs, building abstractions from them, then abruptly discarding them and going on to a new one.

Eubanks’s developments were far more dizzying. On “Ghost Dog Blues” (not really a blues, but soulful in abundance), he went to a new platform every few bars: stinging blues riffs a la B.B. King stretched into complex, jazzy lines of melody, gnarled themselves into blindingly fast tangles of notes and then became a blur under Eubanks’s rock-ish distortion effect.

He also used a volume pedal to vary his dynamics, which became a distraction on “All Blues,” when his accompaniment threatened to drown out Pierce’s solo. If Camacho couldn’t match their versatility, it was just as well. He was solid as a rock, the stabilizer that kept the tunes’ rhythmic and melodic shapes from dissolution.

Eubanks remained recognizable to the audience, however, through the effortless charm people came to know on television. He was quick with a warm smile and funny aside, as when he dedicated “Ghost Dog Blues” to his friend Arsenio Hall. “I wish him well on ‘Celebrity Apprentice,’ ” Eubanks said. “I don’t even know what that show’s about, but since he’s on it . . . .”