In 1998, a crew of four like-minded musicians crossed paths at a jam session up in the mountains of Nederland, Colorado. They drank brews and improvised a few songs, quickly picking up a strong harmony and rhythm playing music altogether. With nothing to tie them down at the time, the four young guys decided to take a leap and form what would become Yonder Mountain String Band.

A near quarter-century later, YMSB still thrives on that impulsive, experiential nature. And the progressive bluegrass group continues to make their mark in the live music scene today, bringing their adventurous spirit to countless venues across the country.

YMSB’s next stop is The Arts Campus At Willits in Basalt for a show taking place on Tuesday at 8 p.m. Tickets are still available to purchase through the TACAW website and will increase in price after today.

While YMSB has played at many different Roaring Fork Valley venues over the past two decades — including Belly Up, the Wheeler Opera House, a Jazz Aspen Snowmass performance and multiple spots in Carbondale — this will be the jam-grass act’s first time performing at TACAW. Having a strong fanbase in the valley and with Colorado in their blood, it’s a performance which the members of YMSB are very much looking forward to.

YMSB is currently composed of founding members Dave Johnston on banjo, Ben Kaufmann on bass and Adam Aijala on guitar, as well as the group’s newcomer Nick Piccininni — a multi-instrumentalist who joined YMSB in January 2020 and plays the mandolin, second fiddle or anything stringed.

Also joining YMSB during Tuesday’s performance at TACAW will be fiddlest Jake Simpson, who has recently played alongside the band for a handful of shows of which Kaufmann described with enthusiasm.

“The energy that I’ve felt from the way we’ve all been playing together on those stages has been next level,” Kaufmann said. “I think the band is hot fire right now.”

YMSB is often recognized for its energetic presence on stage. Whether performing a sold-out show at Colorado’s iconic Red Rocks Amphitheater or playing late night jams along the streets of San Francisco’s stripper district, spontaneity and creativity characterize YMSB’s live performances — something Piccininni caught right onto when joining the crew of musicians.

“The anxiousness or the anticipation of being like, well, this could go either way, I think gives the music itself an edge, too and also a sense of excitement that people pick up on,” Piccininni said.

Aijala chimed in, stating that YMSB has always had that element of “flying by the seat of your pants.” He explained that throughout the band’s almost 25-year run, they’ve expanded the boundaries of the bluegrass genre, considering both the diverse mix of influences — from the Grateful Dead to punk rock — which have affected their covers and original songwriting, as well as their experimentation with live jams.

YMSB’s extended musical improvisations have attracted more of a freewheeling jam crowd than the traditional bluegrass scene. In turn, YMSB has exposed a whole new generation of fans to bluegrass.

Johnston added that he and his fellow band members value creativity over perfection, and he credits YMSB’s quarter-century lifespan to its “informality” aspect.

“You know, I don’t think we’re as [steady] and stuffy as some of the other bluegrass bands that were out there when we started,” Johnston said. “We take a looser approach in trying to connect with the audience as a shared experience as opposed to it being like a presentation — I think that’s a big part of why we’ve been around for so long.”

Since its inception, YMSB has been taking risks, Kaufmann said. The crew of musicians found themselves early on playing and crafting a different sound and musical ­experience than others in their genre, fusing jam band and rock music into traditional bluegrass.

“Even with other bands that were kind of dipping their toes into that water, it wasn’t quite the same as the leap off the cliff that we took,” Kaufmann said. “And that’s what set us apart.”

Tuesday night’s YMSB performance at TACAW will begin at 8 p.m.; doors open at 7 p.m. Tickets for the standing show are $55 in advance ($65 day of) and available to purchase at tacaw.org.

Jacqueline Reynolds is an arts & entertainment reporter for the Aspen Daily News. She can be reached at jacqueline@aspendailynews.com.