The 1970s saw the debut of a new generation of bluegrass musicians, young people weaned on the masters but dedicated to exploring different ways of playing the acoustic music of Appalachia.
There were the Dillards from Missouri and California, there was New Grass Revival from Kentucky and, from the burgeoning hippie bohemia of Boulder, Colorado came Hot Rize.
All of these bands were charting new territory, and having a blast doing it.
"The carrot at the end of the stick was just enough to keep us going," says Tim O'Brien, whose mandolin, guitar and vocals were front and center in the Hot Rize mix. "There was always another carrot.
"We just wanted to play some traditional bluegrass with a little bit of a difference. We knew we were not going to be Bill Monroe and the Blue Grass Boys, but we wanted to honor those guys as much as we could. We were just crazy about that first generation - Flatt & Scruggs, the Stanley Brothers, Bill Monroe."
The Tim O'Brien Band makes its first Savannah Music Festival appearance this week, with a quartet of shows at the Morris Center.
The Infamous Stringdusters, an even younger and more experimental bluegrass outfit, will open the concerts (O'Brien, who's now one of the "grand old men" of modern bluegrass, produced one of their albums).
O'Brien says he firmly believes that the passion for innovative acoustic music skipped a generation. "My older son, he doesn't want to play music like I play," he explains.
Ah, but things are getting exciting again. "It's growing all the time," O'Brien adds. "It's like a big tree where the roots and the branches are healthy. They're just shooting out like crazy right now."
For example, "Chris Thile is the lab standard now. He's the up-to-date model. But people are coming to bite his butt, too, don't worry about that. There's some kid that's learned everything he does now and is going to expand on it. That's just the way it works, it keeps growing."
Thile's Punch Brothers - they played the festival April 2 - are doing things that make O'Brien sit up and take notice. "I get really excited about that," he says. "I hear that stuff and I go ‘Man, this is really the right thing to do. This is exactly what we should be doing here, expanding the song forms, re-defining the roles but also re-enforcing the old roles of the instruments in the music.'"
Although he's played with everyone from the Chieftains to Steve Martin to mandolin maestros David Grisman and Mike Marshall, O'Brien is the focal point of the band that bears his name.
Not that they're just your run-of-the-mill pickers. For the Savannah dates, O'Brien's band includes Bryan Sutton, a veteran of Ricky Skaggs' Kentucky Thunder and the International Bluegrass Music Association's five-time Guitarist of the Year; fiddler Stuart Duncan, who's part of the "T Bone Burnett Franchise" (to use O'Brien's words) and recently worked extensively with Robert Plant and Alison Krauss, and Elvis Costello; and standup bassist Mike Bub, a longtime member of Del McCoury's band, and the winner of the IBMA Bassist of the Year award for five years running.
O'Brien's latest project is a "family band" recording ("with my nieces and my sister and brother-in-law") of songs by the late Roger Miller.
"I've been up to my ears in Roger Miller music," he says. "I've learned a whole bunch more about Roger Miller. I knew the hits, but I didn't realize all this stuff that he did. ‘Chug-a-Lug,' ‘Dang Me,' ‘Do-Wacka-Do,' ‘You Can't Rollerskate in a Buffalo Herd,' that was the stuff that I loved when I was 12 or 13. When I was a kid, the Beatles and that was enough to go on."
And it's all part of the never-ending learning curve.
"That artist is in a room, and there's a door to another room behind him," says O'Brien. "Roger Miller was way into Ray Price and Hank Williams and Bob Wills, that kind of stuff. So you listen to Bob Wills, there's a room behind him with older blues and Bessie Smith, you know? You just keep looking.
"And I keep going back to the Celtic stuff. I'm just so into bagpipes and fiddles without any accompaniment. It kind of frees up the mind, and lets you figure out your own harmony to it. I just love that stuff."
It was that insatiable curiosity that caused O'Brien to accept an offer from the English guitarist Mark Knopfler, to play in his band for a five-week American tour in 2010.
"It was really fun," O'Brien says, "and it was really instructive. I almost turned that gig down, because I'd seen him play, and I didn't think I could stand there and play one or two notes on every song.
"And yet, the pay was really good - and it was a chance not to be in charge of anything other than just concentrating on some music. I didn't have to worry about logistics; I'm kind of self-employed here. I run a business and there's a lot of work besides just getting the music together.
"Also, I really learned a lot about discipline, and how to be concise, and how to really listen. And to be consistent. It was more like being a member of an orchestra. It was an eight-piece band. I also learned what's possible, technologically, that I probably will never be able to afford on my own!"
Savannah Music Festival
Tim O'Brien Band
With the Incredible Stringdusters
Where: Charles H. Morris Center
When: 6:30 and 9 p.m. April 8; 11 a.m. and 1 p.m. April 9
Tickets: $32 (April 8), $25 (April 9)
Sound Dialogue: Andy Falco interviews Tim O'Brien: 2 p.m. April 8, Kennedy Pharmacy. Free