It’s odd that one of the hardest-working jamgrass bands on the national circuit denies their status. With a lengthy set of beautifully crafted country/bluegrass original tunes — many with fine lyrics, rich harmonies, and hot-finger solos — Greensky Bluegrass more than lives up to its name, but singer/guitarist and founding member Dave Bruzza insists that their foundation came from something else.

“We have such a variety of tastes within our band and organization,” Bruzza told City Paper last week, as he and the band were between radio shows and live sets at the massive Bonnaroo festival. “We’re not really a bluegrass band. We’re more of a rock ‘n’ roll band in disguise. It doesn’t really matter what genre a song is. Whether it’s a song we love or a song we want do as a joke for fun, we’ll do it either way.”

The cover of the band’s newly released live album All Access Volume 2, the second installment of their double-disc CD live recording series, features handsome silhouettes of the band walking along with their instrument cases. But none of them are carrying any drum cases. How rock ‘n’ roll is that?

“You don’t necessarily need a drum kit for a band to be rock ‘n’ roll, and it’s the same with bluegrass, where purists say the drums aren’t allowed,” says Bruzza. “That’s the biggest bunch of crap I’ve ever heard. Jimmy Martin had a guy with him playing snare drum — and he’s the king of bluegrass.”

Bruzza initially played drums as a teenager, but his dad and uncle were heavily into bluegrass and folk-rock music, so he gravitated toward stringed instruments.

“I went to see the Grateful Dead when I was young. Then I started seeing hippies playing bluegrass, which led to really getting into the Old and in the Way album [the self-titled 1975 acoustic collection by the bluegrass supergroup featuring Jerry Garcia, mandolinist David Grisman, guitarist Peter Rowan, and others]. I was hooked from there.”

Bruzza assembled Greensky Bluegrass in 2000 in his hometown of Kalamazoo, Mich., with banjo player Michael Arlen Bont and mandolinist Paul Hoffman. They came from varied musical backgrounds, but all three buddies wanted to explore bluegrass and get tight on a slew of standards and obscure ditties. Their debut album, Less than Supper, came out in 2004.

When the three bandmates started out, they simply wanted to learn how to play traditional bluegrass music. There was no Nugent, Seger, Grand Funk Railroad, or other classic Great Lakes rock in the set.

“We did that for a couple of years, playing locally and having fun,” says Bruzza. “We realized that we needed to write our own material and work on new stuff. Over the last few years, we added members and expanded the set lists. It definitely went from one end to the other.”

Shortly after its release, the trio added two additional players to their touring lineup. The current roster features bassist Michael Devol and dobro player Anders Beck.

The quintet won the Telluride Bluegrass Festival Band Competition in 2006, a great feat coinciding with the release of their second studio album, Tuesday Letter. That collection and 2008’s critically acclaimed Five Interstates were produced by Tim Carbone, the fiddler of Colorado’s Railroad Earth.

The band loved the string-based tunes and jams of contemporary acts like Leftover Salmon, String Cheese Incident, and Larry Keel, but they cite the music and attitude of the late John Hartford as a major influence that encouraged them to break out of the box early on. While most of All Access Volume 2 rambles on with bluegrass textures, one can detect a bit of rockin’ in the mix, a hint of jazziness in the jams, and some channeling of CCR and the Dead from time to time.

“The bottom line is, you hear what you hear and what you like is what you like,” says Bruzza. “If you’re going to be really stuck up and tell someone they’re not doing it right, or tell someone they’re disqualified, that’s not cool. If you’re going to be narrow-minded and not open up to something new, then I don’t need ya.”