The frustrating thing about Nicholas Payton's career is that he's still a terrific jazz trumpeter. He proved as much in an exhilarating set with the Fleur Debris Superband in the Jazz Tent at the New Orleans Jazz & Heritage Festival Saturday afternoon. But Payton, frustrated that jazz trumpeters don't get rewarded the same way pop singers do, has steered his own band into a funk group that features his own singing and songwriting as well as some trumpet embellishments. But this has meant that he has replaced his great strength with an obvious weakness. Don't get me wrong; I believe a great funk band can be the artistic equal of any jazz group. But contrary to the condescending assumption of many jazz musicians, it isn't easy to create a great funk band. And Payton's skills don't lie in that area. His gifts lie in instrumental jazz, as he proved again when he joined the New Orleans all-star quartet of pianist David Torkanowsky, bassist George Porter Jr. and drummer Zigaboo Modeliste. The latter two musicians, of course, were one-half of the original Meters and constitute one of the greatest funk rhythm sections of all time. But they have made the leap across the funk/jazz divide more gracefully than Payton has in the opposite direction. Porter and Modeliste kept the band's momentum tumbling ever forward without ever playing any four-bar phrase the same way twice. Torkanowsky, a founding member of the superb New Orleans jazz band Astral Project, did something similar. But the best solos came from Payton, who alternated impressionistic romanticism with serrated edginess. Never adding an unnecessary note, he sculpted out improvisations that sounded like elegant compositions. On Harold Battiste's "Marzique Dancing" and his own "Backward Step," Payton turned moody modal excursions into thrilling explorations. But when the band finally did a vocal number, an R&B tune called "Be My Baby" (not the Ronettes' song), they wisely left the singing to Porter.