Photos: Austin City Limits 2012
Gary Clark, Jr. performs during the 2012 Austin City Limits Music Festival on October 14, 2012 in Austin, Texas.

To an ignorant eye, it seemed to be a typical night inside Hollywood's live performance hub Hotel Cafe. The Austin guitar phenom/vocalist Gary Clark Jr. and his band exited the stage after figuratively shredding it to fractions, as they're prone to do. But this early-2011 exhibition was different, essentially more audition than jam session, as the evening's crowd included a couple of leaders from Warner Music Group-most important, Warner Bros. Records chairman Rob Cavallo. While upright patrons, newly awakened from the trance induced by Clark's electric wah-wah, cheered with an assortment of claps, screams and whistles, Cavallo leaned into the ear of Elyse Rogers, Warner senior VP of global touring and artist development, and asked, "What do you think?"

"I think he's going to be massive globally," Rogers responded.

"I'm going to remind you that you said that," Cavallo said.

"You won't have to," Rogers replied.

When Rogers recounts the story today, her words bounce with affirmation-because Gary Clark Jr. is indeed a comet torpedoing toward international notoriety. The 28-year-old's music, a smorgasbord of rock'n'roll, R&B and the blues, embraces new ears and clamps a vice grip on the hearts of purists. Some are colleagues: Alicia Keys requested that Clark join her onstage for her annual Black Ball charity concert in New York last November, then gushed on its red carpet, "He's so, so special." Jay-Z co-signed, as did President Barack Obama.

They aren't alone. Anyone who's attended any major American music festival this year, regardless of genre-from Bonnaroo to Coachella to Essence to Lollapalooza to Made in America-has experienced the wonder that is Clark in the flesh. Throughout 2012, the climbing star played more major festivals than any other musician, according to the label. This was by design. Before Clark's John Hancock even had a chance to dry on his Warner Bros. recording contract last December, the modus operandi was clear: "Get him in front of as many people as possible who are real music fans," Rogers says today.

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An electrifying EP, "Bright Lights," was quickly released in August 2011 to garner initial exposure and sales (80,000 copies thus far, according to Nielsen SoundScan). Clark was then thrown on the road until, well, put it like this: He says he's spent 75% of the last 18 months touring, something he's grateful for. "I definitely love touring," says Clark, who, appropriately, is in an Orlando, Fla., airport, awaiting a flight to a charity gig in Austin. "This is the best way for me to do it-being on the road and seeing people's faces, as opposed to throwing out a single and hoping it sticks."

"We see all of our developing artists as global artists," Warner co-president/COO Livia Tortella says. "We knew [Clark] was a good writer, but it was really important to showcase his music ability. So, putting him in front of gatekeepers-whether from urban or the rock world-was kind of the magic recipe for Gary as we started to build up."

Success was built through simple addition. With each performance, Clark's fan base grew. Then, along with the commencement of 2012, came some major highlights: He was summoned to the White House to play alongside B.B. King and Mick Jagger for the "Red, White and Blues" event; ESPN teamed Clark with one of his idols, the rapper Nas, to create the theme for the 2012 NFL Draft; and the title track from "Bright Lights" was tapped for the videogame "Max Payne 3." "I'm living the dream," Clark says. "I get to play music without any boundaries, and the people are accepting me. That's a great feeling."

Clark's addiction to music can be traced back to 1988, when, at age 4, he saw Michael Jackson on the "Bad" tour. Yet, it wasn't MJ himself who opened Clark's ears. "[Jackson] had this guitar player, and she had all these lights all over her, glowing," Clark remembers, referring to legendary guitarist Jennifer Batten. "She had a big Mohawk and was just playing wild lead until 'Beat It' came on."

Though Clark was introduced to a variety of instruments throughout his childhood, he didn't adopt the guitar until sixth grade. It soon became apparent he was born to strum: He jammed alongside Texas greats like Jimmie and Stevie Ray Vaughan as a teenager, and even won the Austin Music Award at 17. So it's no wonder that the Warner-brass-attended night at Hotel Cafe was just another hit for the Lone Star gem. He's been rocking Epiphones and Gibsons for half his life. "I try not to get caught up in the 'such-and-such is in the audience' [talk]," Clark says. "I don't feel any pressure once I get my feet on that stage. Either they like it or they don't."

But the magic question is, Will the masses like Clark's work off the stage? There isn't a collection in stores today that matches the near-schizophrenic versatility of his debut full-length, "Blak and Blu" (Oct. 22), which Clark co-produced with Mike Elizondo (Dr. Dre, Fiona Apple). As expected, it's a pungent fruit punch of Clark's experimentation and influences. Sly Stone is saluted with the somersaulting "Ain't Messin' Around"; a bit of Bill Withers' ink bleeds through on "Numb"; Smokey Robinson can be heard on the ambitious "Please Come Home." Then there are cuts like "When My Train Pulls In," where Clark's chordophone play might be the closest this generation has come to Hendrix.

But a possible problem for "Blak and Blu" is that the amorphous body of work doesn't have a definitive section in big-box retailers like Target to call home. There aren't many urban artists on radio today whose songwriting oozes blues and whose guitar-playing breathes rock'n'roll. MTV rotations aren't populated with black men who'd rather go unshaven than smile, whose aesthetic is more Nat Turner than head-turner. That Clark can share a stage with any act from Sheryl Crow to Eric Clapton to Ryan Bingham to the Roots seems an indisputable virtue, but could this range ultimately be more curse than gift? "I don't really know," he says. "People say I'm all over the place, but I don't worry about it. I don't think it can hurt me. It just helps bring folks together. I feel great about [the album]."

Luckily, Warner has a long track record of successful, road-focused rock acts-most notably, the Black Keys, whose rousing blues may be the closest thing to Clark on the market. The duo spent years touring small venues around the country before finally reaping big dividends with its sixth and seventh albums, 2010's "Brothers" and 2011's "El Camino"-which debuted on the Billboard 200 at Nos. 3 and 2, respectively-despite being mostly ignored by traditional radio. Warner anticipates a similar, if faster, journey for Clark. "I don't think [Clark's album is] something radio is going to lead on," Tortella says. "I definitely see it as a slow build. He speaks to so many different people, and touring is the only way to truly show that."

To that end, Clark's release-month itinerary features a litany of high-profile stateside performances, on TV (Jay Leno and Jimmy Fallon) and off (New Orleans' Voodoo Music Experience). Then he'll cross seas to rock with acts including Red Hot Chili Peppers in Australia for the Big Day Out festival. It's a loose, albeit deliberate scheme for success. Rogers says: "[The touring outlook for Clark is] going to be a combination of clubs to theaters, and when the market calls for cool interesting support spots he'll do them."

All this laborious roadwork will further introduce the world to a man many consider the savior of blues. For now, though, the guitar hero has little time to consider any anointment. He must play. Then play some more. Like his life depends on it. "I have moments where I think to myself, 'What am I doing?' and 'I could use a little bit more sleep,'" Clark says. "But it's all good. I get to run around and play shows. It couldn't get much better than this for me."