Greensky Bluegrass has turned a classic American genre on its head

Looking at the poster for this year's event, way down in the fine print, 53^rd on the list, you'll find Greensky Bluegrass, a five-piece American bluegrass jam band that has never set foot in Australia.

Yet, they've made seven studio albums plus a handful of live recordings. They've been touring for almost two decades, doing 175 shows a year, and selling out venues like Red Rocks amphitheatre and playing festivals like Bonnaroo and Telluride.

Their loyal followers are known as "campers", attending several shows a year, not unlike Deadheads who followed another mysterious American band with a twang.

Formed in their university days in Kalamazoo, Michigan, they have evolved to a finely-tuned live act, their own songs loaded with dark, cathartic lyrics bouncing off exquisite compositions featuring dobro, mandolin, banjo, upright bass and guitar, with engaging riffs and solos.

Their covers are mind-bending, like their version of Pink Floyd's Time, repackaging its message for a new generation, or When Doves Cry by Prince, and A Day in the Life by The Beatles.

Paul Hoffman, the band's chief songwriter and mandolin player, is minding his nearly one-year-old daughter, Juniper, in his arms at home in Denver when we talk. He's been there for the entire ride, starting at age 19 and now looking back, at age 38, at their journey.

Are you making music that will be remembered, I ask.

"I wonder if, in the story of bluegrass, if we just are a road stop, a landmark on the path of what bluegrass was and will become," he says. "We started as a pretty straight-ahead bluegrass band, trying to learn how to play bluegrass correctly. And then we started to write material, come up with our own style ... we incorporated all the things we liked that are not bluegrass, kind of pulled it away from a traditional sound.

"But, in the same respect, we have a lot of respect for bluegrass music, that's where we came from. In a way we expose people who don't know about bluegrass to bluegrass, as far as our part in whatever our genre is, maybe we are just part of a story that will serve a time ...

"Maybe there will be people who look back at a time when there were all these jam bluegrass bands who did rock 'n' roll bluegrass. Maybe people will keep doing it. I would. Maybe it will go out of vogue, I don't know."

Where do the dark lyrics come from?

"We write a lot about the experiences we have on the road, the longing for stability, but the need for reckless wandering," Hoffman says. "A lot of those feelings, I think they are transcendent of what everybody goes through ...

"So we sort of embrace the things we know, and apply them to the things that everybody is going through. What's more important: your successful career, or find someone to give your love to ... the questions that people balance themselves with, fear of responsibility, regret."

"... If I find something is hard to say, or hard to sing, I sort of hope that it will feel the same way for the audience ... for the fans, and listeners, and perhaps singing along with me might help them let go of that struggle a little bit for themselves.

"Maybe if they didn't even know how to say it ... They will feel their load lightened from music. We want it to be fun, to make you feel better, even if it is sad and dark."

This year the band will once again host Camp Greensky in upper Michigan. It gives those dedicated fans a chance for total immersion.

Do the boys find themselves playing all night?

"Man, in the old days of the band, when we used to play morning sets at festivals and stuff, and not get a lot of exposure, we would stay up all night playing in the campground, meeting people. We don't do as much anymore because we're heading to a airport heading to another festival ..."

Once we're on that subject, Hoffman segues into what a bunch of rebels the boys are, even after nearly 20 years of playing bluegrass.

"I think that feeling, and spirit, when people don't know if we're a rock n roll band or a bluegrass band, I tell them that we're a rock 'n' roll band in spirit. Rock 'n' roll is about defying rules, putting your heart and emotion, putting on a show and all that kind of stuff. Cause that's the kind of rock 'n' roll we embrace. We happen to play bluegrass instruments, and sometimes it sounds bluegrassy, but we've got a a lot of attitude, disrespect for rules ... all that kind of rock 'n' roll stuff."