Trombonist, people connector, entrepreneur and scene inventor: Adam Theis is all those things. A one-man Bay Area music industry for 20 years, he is founder of the loose-knit collective known as the Jazz Mafia – dozens of musicians participating in the umpteen bands that have sprouted from Theis’s renegade brain. Lately, he’s been jumping on his skateboard while practicing his trombone, improvising off the rhythms of the board’s wheels as he rolls up and down a ramp in downtown Oakland: “Something will be developing out of that,” he says. “Maybe a band, maybe a song.”