According to Cash Money's co-CEO Ronald "Slim" Williams, Wayne's success has everything to do with the work-hard/no-play ethos his label boss/father figures drilled into him. "Instead of getting caught up with all the things that come with being an artist in the music industry, he stayed focused on being the best," Williams said. "While everyone was running around partying, he was in the studio, working, practicing his craft."

Following Weezy for four months as he toured the world last summer, "The Carter" director Adam Bhala Lough captured a portrait of the artist as a young workaholic -- a guy whose rap braggadocio and sexual bluster can't disguise that his only real solace is creative release. Schlepping a mobile studio in a black bag with him, Lil Wayne is shown laying down vocals wherever he goes: in hotel rooms and tour buses as well as professional recording booths. He writes down nothing, improvising sophisticated rhyme schemes and spitting tightly calibrated pileups of goofy jokes, disses and cultural allusions on the spot.

"It's breathtaking what comes out of this guy's mind," said Lough a day after the movie's premiere in Sundance. "I wanted to have these long, unedited takes where you'd see Wayne's raw performance on camera. You can say, 'He's just rapping.' No he's not! It's like performance art."

Added Quincy Jones III, producer of "The Carter": "You can tell that he's fearless in terms of trying new things. Having worked with Tupac, [Wayne] reminded me of him in that way. He's excited about being good and the sales numbers are secondary."

For his part, Lil Wayne seems intent on not over-intellectualizing his process. "I just record, man," Wayne says in "The Carter." "Whenever, wherever. It doesn't matter. I got thoughts in my head all day, every day. So to get to the studio, it's a release for me. The [stuff] I got to get it off my mind. Stop thinking about it and stuff."

Rudolf feels Weezy found his mojo by seizing upon a kind of relentless creativity that's unique to hip-hop. "It's fascinating to watch Wayne doing his thing," Rudolf said. "I respect him as a rapper, an artist, a musician. He's a leader."

'Sizzurp' fatalities

Cough syrup might seem a random drug of choice for anyone unfamiliar with Southern hip-hop culture. But within certain Houston precincts, it is as commonplace as smoking copious weed (something else Lil Wayne is caught doing in "The Carter"). The high you get from syrup -- or "sizzurp," à la the Three 6 Mafia's "Sippin' on Some Sizzurp" -- can be woozily euphoric. It spawned a sub-genre of Texan rap called chopped and screwed in which a song's tempo and a rapper's vocal pitch are slowed way down to sonically replicate the soupy fog of a syrup buzz.

Which wouldn't be much of a problem if so many people in the hip-hop community hadn't died as a result of complications from sippin' on sizzurp. Among them: the guy who started the chopped and screwed genre, DJ Screw; Pimp C of the rap group UGK and Houston rapper Big Moe.

As first pointed out by Vibe magazine, Lil Wayne has done little to camouflage his affection for sizzurp, rapping "I'm probably drinkin' that syrup/Thinking I won't slip/Even though I'm leaning like a broken hip" in 2005's "Lock & Load."

But that lifestyle choice hasn't come without consequences. In "The Carter," Lil Wayne's childhood friend/DJ/manager/president of his Young Money label imprint Cortez Bryant is so upset by the rapper's affinity for syrup that he refuses to travel on Weezy's tour bus.

"He knows it's a sickness," Bryant says in one scene. "But what it is, deep down, I don't think he wants to be dead. But it got to that point. It escalated."

In the documentary, Lil Wayne (shown in a YouTube clip from a concert last January) denies being in the grips of any addiction. "A junkie can't do what . . . I do," he says. "I am the ultimate high. I am my drug."

It's a strange moment in popular culture when one is forced to consider a first-time Grammy nominee celebrating a potential win not by hoisting a flute of champagne but by chugging purp from a Styrofoam cup. "I'm amazed that Lil Wayne is the darling of the 2009 Grammys," Vibe's Smith said. "But his presence and impact are undeniable."

And yet come April, with "Rebirth," Wayne risks polarizing his fans with his rock star reboot.

"People will be surprised how good a job he did on this record," said Cash Money's Williams. "Some people would be scared to take that chance. You got to have heart to go out in that water and swim with those sharks. He got that heart. He ain't scared to try nothing."

chris.lee@latimes.com