Members of the Allman Brothers Band, together for more than 30 years, are amazed when they look out from onstage to find young fans in the crowd singing along to tunes written before they were born.

"The fact that the band has been together this long and is still going strong is pretty amazing, and it's not in the slightest bit a nostalgia act," says Warren Haynes.

Originally a fan, the 43-year-old guitarist now has more then a decade of brotherhood under his belt and will join the group when they play the Bluesfest Main Stage tonight.

The group's new album, Hittin' The Note, is their first studio effort in almost nine years and also the first with a new lineup in which original brother Dickey Betts is notably absent. Members gave Betts the boot in 2000, citing "creative differences."

But rumours have circulated about conflicts over alcohol and drug use, with gravelly voiced frontman Gregg Allman having fought his demons and been clean and sober since the mid-1990s.

Any band that's been around for so long is going to have times where everyone is not getting along, says Haynes, who chuckles and likens backstage at an Allman Brothers Band concert circa 2003 to a "much more a wholesome, family atmosphere."

"The thing that I'm really happy about right now is that not only does the band sound amazing, but everybody's getting along great," he says. "Everybody's kind of got their head space in order."

The Allman Brothers Band formed in 1969 when guitarist Duane Allman and his brother, vocalist and organ player Gregg, began playing together in their home state of Florida. They released two albums before their breakthrough 1971 release Live at the Fillmore East.

Shortly after, Duane Allman was killed in a motorcycle accident in Georgia. In a tragic coincidence, Oakley died a year later, also in a motorcycle accident.

But members bounced back, in the ensuing years cementing the group's reputation as one of the States' most influential and skillful improvisational rock and blues groups.

Not ones to compose radio-friendly hits, the Brothers are a classic jam band. They are almost as likely to launch into a side riff or double-drum solo as The Grateful Dead, the group they picked up thousands of dedicated concert-goers from when lead singer Jerry Garcia died in 1995.

They have released more than a dozen successful albums, including 1973's successful Brothers and Sisters, which produced the hit Ramblin' Man (a tune which seems to have been dropped from play since Betts' departure). But inner conflicts and squabbling led to breakups in the late 1970s and early 1980s.

These days the rejuvenated and reconfigured Brothers routinely draw more than 20,000 fans to large, outdoor venues like the Bluesfest and sell out smaller theatres -- like their annual spring runs at New York's Beacon Theatre -- for weeks at a time.

The lineup includes founding members Gregg Allman, who besides being known for his music was also famously married to Cher, and drummers Jaimoe Johanson and Butch Trucks. Trucks' nephew Derek has slipped in on slide guitar, while Marc Quinones fills in on percussion and Oteil Burbridge plays bass, filling ia void left by the 2000 heart failure death of former bassist (and member of another Haynes' jam band called Gov't Mule) Allen Woody.

Bluesfest executive director Mark Monahan had been trying to book the group for the past several years, but their schedules wouldn't allow it. Now that he scored them, for their first-ever Ottawa show by the way, Monahan said organizers are expecting tonight's show to be one of the biggest draws of the 10-day festival.

"It's sort of a great fit for a lot of our passport holders," Monahan said. "A lot of people love the Allman Brothers."

These days Haynes finds himself busier than ever, bouncing back and forth between the Allman Brothers, Gov't Mule and sessions with one of the Grateful Dead offshoots, Phil Lesh and Friends.

He's also focusing on solo work, having just released a limited edition acoustic, five-song CD dubbed The Lone EP, designed to set up the full-length solo album he's going to release in February.