CHATHAM COUNTY — To hear the Red Clay Ramblers play is to get an education, even when they’re just warming up. A recent evening found the hyper-eclectic band’s core four – fiddler Clay Buckner, pianist Bland Simpson and multi-instrumentalists Chris Frank and Jack Herrick – casually arrayed in the studio behind Herrick’s house.

Between digressive discussions about barbecue, long-ago gigs, porcine anatomy, smallpox vaccines and the inherent appeal of Tina Fey, the Ramblers worked up some tunes for an upcoming folk-festival date, displaying impressive off-the-cuff virtuosity. First up was an old Irish reel, proceeding at an amiable lope with Buckner’s fiddle seeming to dance atop Frank’s accordion and Simpson’s piano.

That in itself was unusual, because piano isn’t an instrument usually associated with Irish reels. But the Ramblers, who mark 40 years in show business this month, have never been much for puritanical niceties. After the number wound down, Frank asked what they’d just played.

“That’s ‘Miss McLeod’s Reel,’ ” Buckner said.

‘Well, that’s the name ‘over there,’ ” Frank said, referring to its Irish origins. “What’s it called over here?”

“ ‘Hop High Ladies,’ ” Buckner said, absently fiddling on the tune’s main riff.

They moved on to another tune that proceeded at more of a stately pace. After working it over some, Herrick (who identifies himself as “a junk man who’ll play anything that fits in the van”) rooted around his closet and emerged with a bouzouki, an eight-string Greek instrument. That gave it more of a droning, almost Middle Eastern flavor.

“Yeah,” Frank quipped, “that’ll be on our upcoming album, ‘The Red Clay Ramblers Play “Hava Nagila ” – all Jewish numbers!”

That was a joke, right?

“Well ... with us, you never know,” Frank said, prompting Simpson to recall when the Ramblers actually played “Hava Nagila” at a wedding. And just for the heck of it, they fired it up and it wasn’t half-bad – in case you were wondering what a Hebrew folk song might sound like done up in a quasi-old-time hoedown arrangement for accordion, fiddle, piano and bouzouki.

“Et cetera, et cetera,” Buckner drolly noted as the last note faded.

Fresh take on old-time music

The Red Clay Ramblers first came together in the fall of 1972 as a trio of banjo player Tommy Thompson, guitarist Jim Watson and Fiddlin’ Bill Hicks. From the start, they put a highly idiosyncratic spin on old-time music, adding elements of vaudeville, jazz, blues, music theater and whatever else struck their fancy. Hicks described them as “a band that might have existed in 1930, but didn’t.”

Through myriad changes, the Ramblers have retained the ability to make old music seem new and new music seem old, in the process becoming a Tar Heel institution (and not just because their name is a riff on bluegrass forefather Charlie Poole’s Depression-era band, the North Carolina Ramblers). They headlined the first Festival for the Eno in 1980 and have since played everything from Broadway stages to military bases.

Enough time has gone by for the lineup to turn over completely a couple of times. Hicks and Watson had both departed by the mid-’80s, leaving Thompson to carry on with replacements. One was singer/songwriter Shawn Colvin, a member in her pre-pop-star days. Alzheimer’s forced Thompson’s retirement in the early ’90s; he died in 2003.

But they’ve been a model of stability the past quarter-century. Of the core quartet that still plays as the Ramblers (augmented by others onstage), Frank is “the new guy” – and he joined in 1987 as Colvin’s replacement. Through it all, a band-of-equals egalitarian spirit has served the Ramblers well, even if it left old-time purists confused.

“In the early days, we were criticized for that,” Herrick said. “I remember a guy coming up at a festival once and saying, ‘I don’t like it that all you guys talk onstage. You oughta get just one guy to do that.’ That struck us as something to ignore with all due haste and fervor. It’s probably got something to do with the band’s longevity.”

Co-founder Thompson has been absent from the Ramblers for nearly two decades. But in many ways, they still bear the larger-than-life mark he left behind.

“Tommy was a very deep and complex man,” Simpson said. “But onstage, his entire purpose was high musical style and wit and merriment. He suffused the band with that merriment quotient, which we couldn’t help but carry on. Tommy never vocalized such a thing – it’s just the way he led the troupe.”

Making music for movies

The Ramblers’ first four decades have seen some disappointments, including a planned Broadway run of their musical “Lone Star Love” that was canceled after a falling out with star Randy Quaid in 2007. But they’ve had a lot more triumphs, conquering Broadway with “Fool Moon” in the early ’90s and collaborating with numerous local and national theater and dance companies.

They’ve also had a long and fruitful association with director/playwright Sam Shepard. The Ramblers served as pit band for Shepard’s1985 stage production “A Lie of the Mind” (starring Harvey Keitel, among others). Shepard also put them onscreen as a medicine show band in 1994’s “Silent Tongue,” which was the late River Phoenix’s final film.

If all goes according to plan, more big-screen work could be down the road. There’s a feature film that Simpson is very keen to make happen, based on a North Carolina-centric book he doesn’t want to name just yet.

“We wouldn’t direct it, but get it off the ground,” Simpson said. “Find the money, producer, director. And we’d do the soundtrack, maybe more. Sam (Shepard) put us in ‘Silent Tongue’ playing bit parts, so maybe some of that. Part of the fun of this anniversary is to reflect forward, think about things we want to do and different ways to put entertaining musical narratives onstage. A musical theater piece is different from a dance piece, is different from a concert in a big hall, is different from a concert in a club.”

The Ramblers have done all of that, and more.

“The playing is better now than it’s ever been,” Frank said. “We are unique in what we do, a niche of one. We’re not a bluegrass band or a string band or an old-time band or a Dixieland band, but all that and more. The bottom line is we like each other and have fun when we play, and we know each other so well. I can play with Clay Buckner better than anybody because I learned the tunes from him, and I always know when he’s ready to stop. It’s such a huge repertoire we’ve played over the years, and I feel like our best music is still to be played. I feel pretty good about that.”

Menconi: 919-829-4759 or blogs.newsobserver.com/beat