The Independent may only be a third of the Fillmore’s size, but drawing 400 people on a Wednesday in one of America’s most competitive music scenes is still a feat for a traveling band from Vermont. While Grace Potter’s down-home beauty and charisma probably help her get a first look from many, it’s her talent that’s made her a rising star. Tonight Potter, playing with the Nocturnals, alternates between B3 organ and a Flying-V guitar throughout the set, proving herself a multi-instrumental threat. This makes her a rare commodity in an age when most aspiring pop stars would rather hit it big on American Idol than put in the time and effort required to master an instrument. With a voice that oozes classic rock and blues — at times recalling artists such as Bonnie Raitt, Susan Tedeschi, Stevie Nicks, Sheryl Crow, and Janis Joplin — the 24-year-old Potter is a talent light years beyond the Idol crowd. In early highlight “Stop the Bus”, Potter energizes the packed room with some funky organ work and syncopated rocking. She switches to guitar in the middle of the song, and her short red-and-white dress reveals shapely legs that elicit a few catcalls. But rather than just stand there looking pretty, Potter proceeds to rock out on the Flying-V. “Here’s to the Meantime” features some bluesy slide work from guitarist Scott Tournet that recalls Beggars Banquet-era Rolling Stones. The more you listen, the more it seems Potter would fit right in on a bill with the Stones — or Allman Brothers Band, or Jefferson Airplane. “Take It All Away” keeps things rocking, with Potter pounding so hard on her organ that she breaks one of the keys. The energy continues to surge with “Sweet Hands”, as Potter wails in a way that would do Robert Plant proud. Tournet, meanwhile, delivers more scintillating slide guitar, now recalling Led Zeppelin’s “Traveling Riverside Blues”, while bassist Bryan Dondero and drummer Matt Burr form a rock-solid rhythm section that gives Potter a firm foundation from which to work. A cover of the Who’s “Gettin’ in Tune” proves a superb choice, enabling Potter to display her full vocal range — from breathy pop vocals to full-on power belting. As with the best covers, Potter makes the song sound like she wrote it. When she sings, “I’m singing this note ’cause it fits in well with the chords I’m playing,” she in some ways summarizes the entire show. The Who classic is followed by a new song. Potter begs the crowd’s indulgence: “You guys are our guinea pigs,” she says as the band ramps into “Sinking Man”, a rocker featuring Potter on guitar and a stinging solo by Tournet. One of the evening’s top highlights, “Nothing but the Water”, starts off with a southern Bayou blues vibe before transforming into a turbo-charged funk rocker. The song features a polyrythmic jam session interlude that consists of all members of the band joining together on various parts of the drum kit, led by Potter thundering away on the bass drum. The band then segues into a powerful cover of Neil Young’s “Down by the River”. Starting out at a slower tempo than the original, the Nocturnals version adds a hypnotically moody quality that takes advantage of Potter’s sultry voice. The song builds slowly, with Potter once again moving from organ to guitar mid-song to meet the band as they launch into a Crazy Horse-style jam. A final encore of “Big White Gate” caps off the evening with more of the bluesy vibe that gives Potter the impression of being seasoned beyond her years. The song starts off with a gospel-ish intro that features Potter on organ and Tournet on slide and sets the mood for catharsis. Potter calls to the heavens as she sings, “Saint Peter won’t you open up the big white gate/ Cause I heard about forgiveness and I hope it ain’t too late/ I ain’t no holy roller but you go tell your king/ That all the folks up in heaven might like to hear me sing.” Music fans can count their blessings; it looks like Potter is just getting started here on Earth.