Iconoclasts, by definition, don’t fit in, but the mainstream sometimes peaks around the corner to embrace their contributions. Not looking for acceptance, though, the pioneers have often moved on by then, miles away from their former way of thinking that’s finally settling into the fold. Dr. Eugene Chadbourne is no exception: An electric rake-playing protest singer, a folk enthusiast who recorded with Red Clay Ramblers and Camper Van Beethoven, and an improvisational pioneer who’s collaborated with like minds from John Zorn to Evan Parker, Chadbourne’s bordered on fame, even playing a part in a Wes Craven film. But he still lives in Greensboro, and he brings his ever-evolving ideas into intimate venues across the world.

Jimmy Carl Black touched on fame, too, as the original drummer for the Mothers of Invention. The self-named “Indian of the group” (he has Cheyenne heritage), he was the guy besides Frank Zappa with a big mustache and long hair. Black, who now lives in Germany, continued in left-field operations that branched off of Zappa’s crew like gnarled roots from some baobab tree, but few realize Chadbourne and Black saw eye-to-eye and, later, strings-to-drums. The pair made homage to a shared personal hero, Don Van Vliet, or Captain Beefheart. Black played with him years before. As The Jack and Jim Show, Chadbourne and Black worked through Beefheart and Zappa compositions, kneading the muscle that runs through the great weird and brilliant American poetryhot and bothered, a little fried, still staring at the sun. The Doctor’s sub-genre has long been called LSD C&W, after all.

Chadbourne and Black speak in a language that has no dictionary but many readings, and damn it, humor amid the serious work. This irreverence makes their music burn in the face of mass-programmed music-makers and lifeless stares of listeners. Chadbourne, a conscientious objector during Vietnam, has long applied the same vigor to politics as he has music. Some folks have come around to his corner, and some, luckily, have noticed the unmistakable work of both musicians. They carve paths through a muck others are still snaking.

Dr. Eugene Chadbourne and Jimmy Carl Black play The Cave as The Jack and Jim Show on the “Bushworld Leg” of their Think 69 tour, Thursday, Sept. 6. The show starts at 10 p.m. and costs $10.