THOUGH SEPARATED by decades, two groups at the TD Canada Trust Vancouver International Jazz Festival share a loose, retro approach to playing.

Roy Estrada is the bassist for the Grande Mothers, Frank Zappa’s original band. He remembers recording mid-60s left-field classics Freak Out! and We’re Only In It For the Money. Zappa disbanded the lineup in 1969, beginning an increasingly clean, technical sound focused on complex compositions.

“(In the 70s) Frank was auditioning musicians — being a taskmaster, and focusing more on technique and what was written,” Estrada said. “We have to be on our toes, because of the crazy time signatures we’re playing, but try and play with more soul.”

Jared Tankel plays baritone sax for relative youngsters the Budos Band, 11-piece ‘Afro-Soul’ artists and sometime collaborators with Staten Island neighbours the Wu-Tang Clan. They combine late-60s funk, soul and Ethiopian Jazz.

“Sometimes people ask us why we don’t incorporate more modern elements — electronics, turntables, this n’ that — but that’s not what we’re trying to do,” he said. “We’ve all struggled with the jazz music approach that’s really theoretical and academic — it almost lacks a certain feeling and soul.”

Both groups noted a focus on technical precision can cost warmth. And while cerebral music has its place, they search out warmer, retro sounds.

“Groups that try to be perfect can sound robotic and sterile,” said Estrada. “That idea of a group of guys starting off in a garage, working on their own material which they go out and play … I think that we’re returning to that.”

Tankel agreed. Along with trimming songs to four minutes, Budos Band work with music that influences everyone from mid-90s rap producers to pop songwriters.

“I love that era’s sound, and it doesn’t surprise me that there’s interest — whether it’s aficionados looking for 45s or pop song producers looking for a more retro sound,” he said. “There’s a richness to it that’s really been lacking in the past 20 years of pop.”