Bruner grew up in Compton and other regions of Los Angeles. His mother, Pam Bruner, plays flute and percussion. His father, Ronald Bruner Sr., is a drummer who’s played and recorded with Diana Ross, Gladys Knight and the Temptations. Bruner remembers accompanying him to performances as a child and dozing off during his father’s drum solos.

At Locke High School in Watts, Bruner played in the Multi-School Jazz Band, run by a music teacher named Reggie Andrews. Andrews, who taught at Locke on and off for 40 years, is probably best known for co-writing the Dazz Band’s immortal “Let It Whip.” In the course of his tenure at Locke, he nurtured artists like Patrice Rushen, Tyrese Gibson, members of the Pharcyde, the jazz drummer Ronald Bruner Jr. — Bruner’s older brother — and Bruner himself, who refers to Andrews as his “second dad.”

Through Andrews and the Jazz Band, Bruner reconnected with a tenor saxophonist named Kamasi Washington, who’d grown up in nearby Inglewood but attended Alexander Hamilton High School in West Los Angeles. Washington and Bruner had met as children, when their fathers played together in what Washington called a “gospel-fusion band.”

“Stephen was always who he is, way before it was cool to be that way,” Washington said. “He’s always been a completely unique individual. I’ll never forget, we had a gig one time, and we were supposed to wear all black. I came to pick him up, and he was like, ‘Man, I don’t think I have any black pants.’ I was like, ‘You’ve got to have a pair of black pants.’ He went in his closet. Purple, green, orange, canary yellow, but no black.”

Bruner’s parents were strict about curfews, but being musicians, they saw Washington as a positive influence, Bruner said. “They didn’t have to worry if we were out trolling and being idiots,” Bruner said. “They almost didn’t have to worry about chicks — because we were nerds.”