When Mike Watt steps into Sacred Grounds, a coffee shop and venue in the working-class port town of San Pedro, California, he’s received like the mayor. Fist bumps and pleasantries are exchanged with the patrons. Watt spots me at a back table and ambles over on wobbly knees that affirm his fifty-eight years. He greets me with a firm two-handed grip, peers over his eyeglasses, and introduces himself like a punctuation mark: “Watt!”

Getting coffee with Mike Watt in San Pedro is like having tea at Abbey Road with Paul McCartney, or meeting up with James Jamerson at Motown’s Hitsville USA studio; Watt’s bass playing put this town on the punk-rock map. Watt has resided in San Pedro since age ten, and we’re seated a short distance from the port of Los Angeles, a harbor from which his father, a naval officer and Vietnam vet, often shipped out to sea. The Minutemen, the band he cofounded with D. Boon (who played guitar and shared singing duties with Watt), celebrated San Pedro in song, but came to an abrupt and tragic end when Boon died in a van accident in 1985, at age twenty-seven. Over the course of our chat, Watt frequently steers the conversation back to his father and Boon. Both men led short lives but remain attached to Watt like phantom limbs.

I first saw Watt play bass live on a Lollapalooza side stage when I was fourteen. He strummed with an egg whisk instead of a pick, and banged on the strings with his fist. He was wild without being flashy. He’s a committed student of bass guitar, and adheres to a philosophy of the bass as a supporting role. Since the horizontal electric bass’s invention, in the 1930s, Watt can be counted as one of the players who pushed the four-string into uncharted territory.

From the punk-funk of the Minutemen to the jazzy rock of fIREHOSE to the thunder of the reunited Stooges, Watt maintains a workmanlike approach to music. In recent years, he’s collaborated with younger artists on a variety of projects, including Il Sogno del Mariano, a band with two Italian composers half his age, and CUZ, a collaboration with Sam Dook of the Go! Team. Watt experienced a creative rebirth after the success of the 2005 documentary We Jam Econo: The Story of the Minutemen encouraged him to revisit his past with Hyphenated- Man, a 2010 “opera”—his third—inspired by the band.

Before we sit down, I ask Watt—who’s wearing a red plaid flannel, blue jeans, and black Chucks—if I can get him a coffee. “I’ll take whatever you’re having” is how he responds, gruff and deep. So I...