It might seem surprising if you know the players, but Saturday's convergence of two Boston-based new acoustic stringbands, The Bee Eaters and Crooked Still, at the Arcata Theatre Lounge will be the first time those groups have played together. The common thread between them is Tristan Clarridge, cellist for Crooked Still and fiddler for The Bee Eaters.

Locals know Tristan and his fiddling sister Tashina (also a Bee Eater) from younger days. When they were kids they lived with their mom in a teepee in Burnt Ranch and came down to Arcata to play at the Farmers Market or at local fiddle contests. They got pretty good on those fiddles: Tashina won the Grand National Championship at Weiser Idaho in 2005; Tristan took the same title five times. After years of studying with new acoustic masters like Tim O'Brien and Daryl Anger, they graduated to become teachers themselves. Then a few years ago, Tristan was invited to fill the cello chair in Crooked Still.  

"I'd been aware of Crooked Still for the 10 years they've been together, but I didn't join the band until four years ago," said Tristan, calling from Boston. In 2007, mad cellist Rashad Eggleston left Still to start his own band, Tornado Rider. Fiddler Brittany Haas joined Still at the same time. "We'd known each other for many years through all sorts of music camps. And both of us had the honor of playing with Daryl Anger, a musical mentor," Tristan explained.

Around the same time Tristan joined Crooked Still, he and Tashina formed The Bee Eaters with hammer dulcimer player Simon Chrisman. Tristan had just come out of a couple of years with Anger's Republic of Strings, a period he sees as "like going to music school, a really musically broadening experience." That's where he started playing cello professionally, "taking it to new places."

Because of the cello, one tag applied to The Bee Eaters is "chamber-grass." Tristan figures it fits, but says, "I don't usually even bother trying to categorize our music these days -- it's hard to describe what we do in words."

Crooked Still is celebrating its 10th anniversary with a national tour. Then, Tristan explained, "we're taking a hiatus of undetermined length. We're not done, but we don't know for sure when we'll play together again. With Crooked Still on hold, The Bee Eaters will probably tour more than we have in the past. The calendars were getting extremely complicated. Every member of Crooked Still and all of The Bee Eaters are working in a collection of projects; some overlap members. It created this giant puzzle, which is what the whole Boston folk scene is like. New bands are always forming and membership is always changing."

In some cases the membership shifts are short-lived, creating unique combinations. "For the tour that includes our Arcata show we're bringing guitarist Scott Nygaard as a special guest Bee Eater," said Tristan. "He's been on the bluegrass/newgrass scene for a while playing with Tim O'Brien and Laurie Lewis, and for the last couple of years with Joan Baez. He's just great."

And with both of his bands in the same place, he's expecting lots of collaboration and cross-contamination. "This is the only night of the tour where the two bands play together, so it will have a special kind of excitement for us."

Excitement that comes from doing exactly what he wants to be doing, making music. "We play music because that's what we are -- musicians. Music is in our heads -- we have to play it," he said. "The fortunate thing is there's always someone out there who wants to hear you. With huge corporations taking over everywhere, no matter what happens, people are going to enjoy listening to good music. Musicians are going to make music; listeners are going to listen."

Showtime for the Saturday, Nov. 5, Bee Eaters/Crooked Still show at the Arcata Theatre Lounge is 8 p.m.  Advance tickets are available at the ATL box office, at Wildwood Music in Arcata, at The Works in Eureka and at www.arcatatheater.com.