New York, New York - December, 13: Blues guitarist Gary Clark Jr., poised to be one of the breakout stars of 2012, onstage at the Mercury Lounge on December, 13, 2011 in New York, New York. (Photo by Bill O'Leary/The Washington Post) (Bill O'Leary/WASHINGTON POST)

When Gary Clark Jr.’s right hand hits the strings of his electric guitar, it’s almost always a downstroke — as if he wants gravity on his side. At a crammed Mercury Lounge on Tuesday, the notes fall off his guitar like raindrops. Ripe fruit. Bombs.

Sixties-inspired blues-rock shouldn’t steal your breath so easily in 2011, but Clark’s playing can be almost paralyzing. A dumbstruck front-row fan can’t seem to get his hands to clap between songs. “Wow,” he says, arms pinned to his sides. “Wowwowwow.”

Clark, who headlines sold-out shows at the 8x10 in Baltimore Friday and the District’s Red Palace on Saturday, won’t release his major-label debut album until next year, but some have already crowned him the three-way heir to Eric Clapton, Jimi Hendrix and Stevie Ray Vaughan. But his promise stretches beyond that. The 27-year-old Austin native isn’t resuscitating the blues so much as trying to wrestle it into the future.

“Wow,” says wow guy after a cover of Elizabeth Cotton’s ancient “Freight Train,” which Clark sings as if it were a ’70s R&B ballad conjured from thin air. Then his band dials up the volume and Clark’s right hand becomes a blur, chopping time into fuzzy fragments. Has he been playing this solo for five minutes? Fifty?

It’s easy for Clark to get lost in his music, too. “There’s nothing like just sitting at the house and being by myself with the guitar and just going,” he says. “Four hours will go by, and you’ll be like, ‘Whoa. I don’t know what that was, but I went somewhere.’ ”

Right now, he’s in the Manhattan showroom of fashion designer John Varvatos, where he’s just been fitted for some new suits. After this, he’ll head over to the club for the sound check.

More than a decade after he was first heralded as a prodigy of the Texas blues scene, Clark is poised to become the overnight success story of 2012. In 2001, Austin Mayor Kirk Watson proclaimed May 3 “Gary Clark Jr. Day,” and he’s been recording and touring ever since. He also tried his hand at acting in the 2007 John Sayles film, “Honey­dripper.”

But Clark’s latest, biggest break didn’t come until June 2010, when he turned heads at Clapton’s Crossroads Guitar Festival in Chicago. Warner Bros. signed him soon after and recently released “The Bright Lights EP,” a four-song appetizer that Rolling Stone touted on its best albums of 2011 list as “richer than most full-length records.”

The EP’s standout track, “Bright Lights” brandishes a menacing riff and a refrain that registers somewhere between threat and prophecy: “You’re gonna know my name by the end of the night.”

But where Clark’s music exudes ferocious heat, his personality is all gentle warmth. He speaks soft and slow, his voice barely audible as he reminisces about the B.B. King and Johnny “Guitar” Watson records that his car-salesman dad used to play in the house — records that made him want to play, too.

“It made everything easier,” Clark says of taking up the guitar. “I was kind of a shy kid, didn’t really talk much. I had a lot to say but didn’t really know how to say it. Being able to play guitar, bend notes a certain way and play some chords — they kind of talked for me.”

He never took lessons, opting to learn from a friend who lived down the street. Together, they started sitting in on a Sunday afternoon jam session at Babe’s Bar and Grill. “I knew basic 1-4-5 chords, and then these older guys sort of took us in,” Clark says.

At Babe’s, Clark caught the ear of Clifford Antone, owner of the esteemed Austin blues club Antone’s and mentor to Stevie Ray Vaughan. Before long, Antone had Clark onstage with blues heroes James Cotton, Hubert Sumlin and Pinetop Perkins. “That was my first time playing the Antone’s stage,” says Clark. “I was 15. There are pictures. I still have little X’s on my hands. I had to go to school the next day.”

But when he got to Austin High School the next morning to brag about the royalty he had just noodled around with, nobody knew who he was talking about.

It was emblematic of the splintered musical lives Clark was leading. While he was getting his education in “straight-ahead blues” on the club circuit, he listened to the Wu-Tang Clan and Busta Rhymes with his high school pals. At home, he practiced Motown and Isley Brothers tunes endlessly.

“Instead of trying to separate all of those things, I wanted to throw it all in the pot,” Clark says of his music today. And thankfully, that polyglot approach never sounds contrived. The guitarist says the demo for “Bright Lights” was originally recorded with a drum machine as a hip-hop instrumental. But hip-hop’s intravenous influence on the final product is tough to spot. Still, it’s in there.

And while older fans probably aren’t hearing OutKast or 2Pac in his licks, they have been quick to dub him a savior of the blues. Clark is fine with that, save for the “savior” part. “I think it’s cool that people have confidence in what I’m doing,” he says. “That’s the way I take it . . . It’s great to be recognized as a blues player. I respect the music. I want to tip the hat.”

He also says he doesn’t feel boxed in as he prepares to hunker down and finish his upcoming album. He wants to just let it happen naturally.

“I don’t feel like you can take credit for writing songs,” Clark says. “It’s like tuning into a channel and getting that information and then putting it out. I think it’s about getting the clearest reception and then trying to put it out in the clearest way.”

During the closing solo of “Bright Lights” on Tuesday night, he appears to be doing just that. At a towering 6-foot-5, he stands up on the toes of his black leather boots as he bends the strings of his guitar into pealing ribbons of sound.

It’s as if he’s trying to stand as tall as his music. Or maybe just trying to catch the strongest signal.