Fred Wesley & the Greyboy Allstars

Trombonist Fred Wesley would like to be known for more than just funk and soul. Since the late ’90s, straight-ahead jazz has been the focus of his Fred Wesley Group. “But trying to get back to jazz has been a problem,” he says. “People want to hear the funk, but I found out I can do both.”

You can’t blame his fans. For decades, Wesley was the powerhouse in James Brown’s J.B.s and later in Parliament-Funkadelic, George Clinton’s band. Which one challenged him the most creatively? “That’s a good question,” he says by phone. He thinks it over for a minute. “James did. He was the ultimate challenge for a side man. He came up with the wildest ideas in the world, and I had to put them in force.” But the J.B.s influenced Clinton as well. “George told me to do whatever I wanted to — just make it good. Give up the funk. That was George’s thing. And it had to be good funk.”

Fred Wesley was born in Georgia in 1943. From the start, he aspired to play real jazz. “I didn’t even know who James Brown was. I joined his band just to get to New York and be discovered as a great trombone player.” He also wrote music with Brown and has in recent years heard more than a few of his riffs sampled by rappers. “I didn’t see that coming. At first, I frowned on it. Why can’t these guys make their own music? Then I got the first royalty check, and I thought, Whoa. These guys can sample all they want.”

In San Diego, Wesley will appear as a member of the Greyboy Allstars. They recorded West Coast Boogaloo together in 1995. He says Greyboy was the beginning of the jam-band sound (a group that plays a variety of genres). No jazz here: “You’ll hear some real funky music.”

FRED WESLEY: Belly Up Tavern, Friday, December 30, 9 p.m. 858-481-8140. $30.