If thereʼs any confusion as to why the jam scene has embraced Yonder Mountain String Band more willingly than the bluegrass community, the answer can be found at their live shows, where fun takes priority over purity.

Right from the start of their set at Stubbʼs BBQ in Austin, that ethos was clear: There would be just as much cornball weed humor ( “Granny Wontcha Smoke Some” ) as there would be frenetic picking and soloing at breakneck tempos ( “Pride of Alabama” ).

The Colorado-based quartet have traditional bluegrass instrumentation (guitar, banjo, mandolin and upright bass), and the necessary chops for a demanding genre, but their delivery and demeanor was pure rock and roll – albeit on the goofier, gonzo side, but still rock and roll.

For the first half of the show, the band leaned heavily on standard bluegrass fare, covering The Stanley Brothersʼ “Sharecropperʼs Son” and plucking through their own live staples for shorter, more conventional songs, like J.J. Caleʼs “If Youʼre Ever In Oklahoma.” The improvisational breaks were even more concise, notably those by guitarist Adam Aijala, an airtight flat-picker whose graceful, economic solos worked the entire fretboard, proving that he, more than any other member, had the firmest grasp of traditional style.

After an intermission, the band returned with far more “jam” than “grass.” Songs stretched well past the ten-minute mark, but even during extended soloing, the shadow of bluegrass loomed large. A steam-rolling version of “Didnʼt Go Wrong” featured guest mandolin player Billy Bright whose machine-like precision rubbed off on the rest of the band immediately, stoking interplay to greater technical heights.

The moment that most succinctly captured the bandʼs genre-fusing ethos though, was a brief detour into Pink Floydʼs “Goodbye Blue Sky,” eerily channeling psychedelic, prog-rock auteurs and a ghostly, centuries-old Appalachian choir. The sound was strangely fitting and illuminated a common ground between styles that few people had likely ever noticed, or would even imagine existed.

Transcendence like this was rare throughout the night, but then again, Yonder Mountain String Band wasnʼt aiming for ethereal, anachronistic beauty. Their focus was on playing the music so everyone could have a good time ( “Boatmanʼs Dance” appropriately ended the night) and they executed with expertise, humor and passion, regardless of stylistic etiquette or political correctness.