Glancing at the album titles in the Flat Earth Society’s 20-year discography, you might think the big Belgian jazz band is not only a bit weird, but also twisted. Bonk, Larf, and Psychoscout were followed by Cheer Me, Perverts!, released in 2009 on the ensemble’s own Zonk! label.

However, Cheer Me, Perverts! is simply an anagram of the name of FES’s founder, clarinetist, and principal composer, Peter Vermeersch. And the odd monikers given to songs and albums reflect the importance of offbeat humour for the band, as well as providing easy-to-remember tags for its music.

“There’s no singing, so we don’t get much chance to be on the radio,” says Vermeersch, reached at his home in Ghent. “The only words I can use are in the titles. Sometimes what we do may be thought strange or even difficult—I don’t like those associations—but audiences have no problem getting involved in the music and going with it, and with such titles I can give them a simple key to open up the composition. I like playing to audiences who don’t know us, who may be waiting for the band that comes afterwards at a show or festival but have to listen to us.”

The music of the FES is a rich and shifting mix of jazz, rock, improv, and classical music. “What I like in jazz is the bastard side,” says Vermeersch. “It’s when jazz gets pure that it can get stuck—it’s always taken things from outside.”

The FES’s most recent touring project was a homage to one of the great genre-benders of the past 60 years, Frank Zappa. “It was called Terms of Embarrassment and was supposed to be a Zappa tribute, but I asked the guy who commissioned it if he’d mind if there were no Zappa songs. In the end there are some things, but half the program has nothing to do with him, really. It’s marketing,” says Vermeersch with a laugh.

As a composer, Vermeersch is hard-working and prolific. “I spend seven hours a day writing—and one playing clarinet. I’m hooked on it. Right now I’m working on a documentary about old cruisers in the ’20s—like the Red Star Line, which was sailing from Europe to the U.S. and Canada. They’ve found old film footage which I’m editing—something I’ve never done before—as well as creating all the music. My aim is to have the compositions performed live at the screenings by the band.”

On its third Vancouver visit the FES will be playing original material from Terms of Embarrassment, as well as newer works by Vermeersch that highlight the talents of the band’s 14 members.

“I know the musicians well by now—how they play, what they like and don’t like. But it’s not just me making the arrangements—there are two other guys that I insist should also contribute and do just what they want,” the leader says. “I find it interesting to have a balance between structured and unstructured parts. Our music is open-minded and crazy—always with a big mix of atmospheres, and of course humour.”

The Flat Earth Society plays the Georgia Street Stage at 7:30 p.m. on Saturday (June 25), as part of the TD Vancouver International Jazz Festival.