The Minutemen, a trio from San Pedro, California, may not have been the best or most influential group to emerge from America’s punk scene in the '80s. But no band worked harder to press the point that punk was a system of beliefs, not just a sound. While most hardcore bands at the time knocked out repetitive, machine-gun beats, drummer George Hurley played splattery, jazz-influenced rhythms; Mike Watt played bass like he’d wandered off George Clinton’s Mothership; and guitarist-singer D. Boon rattled off tangled, politicized lyrics that scanned more like Beat poetry than anti-Reagan screeds. When Boon died in a van accident shortly before Christmas 1985, at the age of 27, it was like the scene severed a tendon — a flexibility that once was there was permanently gone.

Tim Irwin’s smart, funny, and affecting documentary about the band makes no great claims about the Minutemen’s genius — in fact, he leaves ample room for numerous scenesters at the time who scratched their heads at the group’s look and sound. Instead he concentrates on the close friendship between Boon and Watt, childhood friends who put together a punk band not so much because they loved the Ramones or the Clash but because they loved the idea of creating their own culture out of whole cloth. They were comically naïve at first, thinking that basic stuff like tuning wasn’t essential; some guitarists liked their strings “loose,” they figured, while others preferred them “tight.” But soon enough they’d invented a spiky, insistent sound that packed a surprising amount of movement into very brief tunes with provocative titles like “Little Man With a Gun in His Hand,” “Bob Dylan Wrote Propaganda Songs,” and “Jesus and Tequila.” (Most listeners figured they were called the Minutemen because their songs often clocked in at under 60 seconds, though Watt debunks that notion in the film.)

In time the band became one of the most popular groups in the stable of the influential California punk label SST Records—home to Black Flag, Husker Du, the Meat Puppets, and Sonic Youth. Much of the reason they were so beloved was their intense belief in supporting the scene they helped create: The film includes footage of the band getting spat on while playing, which inspires Watt’s angry but oddly embracing retort, “You think that’s punk? I’d go see your band.” By the time Boon died, the band had better chops and was playing more conventional music — its final studio album included Blue Oyster Cult and Creedence covers—but it felt more like a choice than a compromise. “Our band could be your life,” was Boon’s signature line; what he meant was, “You have options,” and We Jam Econo is a spirited tribute to the power of that belief.

The We Jam Econo DVD includes deleted scenes, the complete footage of an hour-long 1985 interview with the band, and a handful of music videos.