Though jam-heavy roots rockers Little Feat have long been lumped within the narrow parameters of Southern rock, the California-born troupe’s broad scope of influence reaches farther than just below the Mason-Dixon line.

From their self-titled 1971 debut, back when now-deceased howler Lowell George fronted the group, to the recently released Join the Band, Little Feat has drawn from a broad scope of American music brewing with Cajun fervor, Mississippi blues licks, Memphis soul rhythm, and the wild-eyed weirdness of its native West Coast.

This year marks Little Feat’s 40th anniversary. The original group came together shortly after founding vocalist/guitarist George jumped ship from Frank Zappa’s Mothers of Invention to indulge in something a little more organic and longhair-friendly. Following George’s death from heart failure in 1979, the group called it quits only to reemerge nearly 10 years later with much of the same personnel and a new vocalist, the now departed Craig Fuller, who sang more than a little like wild and woolly predecessor, George.

Today, keyboardist Bill Payne and drummer Ritchie Hayward are the only founding members left in the group, though lead singer/guitarist Paul Barrere, bassist Kenny Gradney, and percussionist/vocalist Sam Clayton joined the Feat family in 1973, just in time to record the essential release Dixie Chicken. They’re all still part of the fold today. Guitarist Fred Tackett, something of an honorary member until the late-’80s reformation, also still proudly dons his sailin’ shoes as the group heads back on the road for its anniversary tour.

Join the Band, the recent commemorative release, not necessarily a definitive version of the band’s lineup, brings together a stable of guests influenced by the group’s catalog. Depending on your preference for some of the wide range of artists, including Dave Matthews, Brooks & Dunn, head Black Crowe Chris Robinson, and Jimmy Buffett, this could be seen as a blessing or a curse.

More often than not, the partnerships provide blessed results. Vince Gill lends his golden throat to a relaxed “Dixie Chicken.” Phish bassist Mike Gordon chimes in for a funky rendering of concert staple “This Land Is Your Land,” and Robinson kicks the tempo up many a notch on hotfoot rocker “Oh Atlanta.” Elsewhere, it’s the ladies who steal the show. Longtime pal Emmylou Harris, with mandolinist Sam Bush and banjo icon Bela Fleck, hit tribute paydirt with the chopping, clapping “Sailin’ Shoes,” while Lowell George’s daughter, Inara, takes the lead on a warm rendition of her father’s karmic ballad “Trouble.”

Of course, fans shouldn’t expect to see these guest artists trotted out when the Feat step soundly into Charleston’s Music Farm. But, Little Feat hasn’t stuck around this long by making topsy-turvy, guest-laden albums. They’ve done so by satisfying loyal audiences as one hell of a stage band that continues to surprise and evolve in the live arena.

A recent shift in vocalists saw the departure of fiery female singer Shaun Murphy and has since put the soulful pipes of Sam Clayton on display. With support from Barrere and virtually the rest of the group at certain points, Clayton’s stout R&B and gospel chops bring new dimensions to old favorites like “Fat Man in the Bathtub” and “Spanish Moon.” Barrere and Tackett’s slippery guitar interplay remains a vital band centerpiece, while Hayward, Payne, and Gradney continue to keep rock-solid rhythm on par with the old Stax session band.

Little Feat, as a live band, rarely fails its diverse legion of fans. And, if recent concert appearances by the six-headed beast from Cali serve as an indicator, they ain’t about to start now.