Cali Roots’ little brother delivers four reggae-rock acts.

Passafire’s lead singer and guitarist Ted Browne says the band is very different than it was when it released its 2006 self-titled debut.

“We were college kids trying to emulate our influences, trying to figure out what made them tick,” Browne explains from an El Paso gas station. “We played a lot of covers.”

Now, they only play originals. Browne attributes one of the main differences to keyboardist Adam Willis departing from the band and Mike DeGuzman coming on board as his replacement.

“Mike brought more of a rock edge,” Browne says. “He also brought a funk-jam-blues background, along with a love for reggae.”

These days, Passafire unleashes a top-notch live show highlighted by extended, improvised jams and even an element of Phish-like onstage theatrics – the band goes around in a circle, switching instruments, until they have each played every one.

The group's Saturday performance at Autumn Roots at the Fairgrounds won’t be their first experience with Cali Roots; last year, Passafire played Cali Roots’ Carolina Sessions in Wilmington, North Carolina.

Passafire’s evolution has yielded a record deal with the prominent Easy Star Records label, who also backs Rebelution and The Black Seeds. Browne believes Easy Star, who put out the outfit’s 2013 Vines, inspired the group to take risks it hadn’t on its four previous records. It debuted at No. 1 on the Billboard Top Reggae Albums chart.

“We didn’t stay in the brackets of our genre,” he says. “We played a bunch of music that came to us naturally.”

Tracks like hard-rock, synth-heavy “Go” barely even hint reggae. That’s not a bad thing. Meanwhile, the acoustic Americana tune “Stowaway” exemplifies just how tight this band has gotten – Passafire’s signature infinite-vacation sensibility remains intact as ’60s-style keys strut along whimsically under the vocals and backbeat.

The Savannah, Georgia quartet just finished laying down drums for new songs at producer Paul Leary’s (Butthole Surfers) renowned Sonic Ranch, where Passafire also crafted Vines.

“Not only is the vibe amazing, every instrument and amp is available,” Browne says. “[Sonic Ranch] is like a resort for musicians with a pool and 3,200 acres of pecan trees.”

New Zealand’s Katchafire, Santa Cruz favorites Thrive and Animo also perform Autumn Roots.

AUTUMN ROOTS 3pm Saturday, Oct. 11. Monterey County Fairgrounds, 2004 Fairgrounds Road, Monterey. $25/advance; $30/door. www.autumn-roots.eventbrite.com