Before Al Kapone's first gangsta-walk down the red carpet -- before his homespun Memphis hip-hop boomed from obscurity into a marquee role in "Hustle & Flow" -- the rapper maintained a decidedly modest business plan:

Get crunk, get paid.

Not brand-new-Bentley, gold-cap-on-every-tooth, biggest-crib-on-the-block dollars, per se; just enough to make rent, fuel up the '88 Oldsmobile, feed the kids and avoid the grimy world of restaurant Dumpsters.

"Before I first started making a little money with my music, I was doing busboy-dishwashing stuff at Red Lobster," Kapone says via cell phone while cruising around Memphis in that 17-year-old Olds. "I'll never forget those rough days, man -- emptying them big garbage cans full of food, seven, eight at a time, your feet soaking wet, that smell. Oh, man! It's serious. SEE-REEE-OUS.

"That's why my career is a blessing. I've never sold a whole lot of albums, but I've made enough money to live and take care of my family and not have to have a job. There's a lot of people doing jobs they hate; I was one of them. And I don't want to go back."

Until recently, the 33-year-old rap careerist sold his CDs out of the trunk of his car, which is pretty crunk when you think about it. (Crunk: It's a noun, but also an adjective. And a verb! Somehow we don't think E.B. White ever pondered this. Crunk: To get cranked-up, sans psychotropics; wild, crazy, off-the-hook goodness; hyper-aggressive rap that's not unlike punk rock for the dance floor. Use it in a sentence? "Crunk is not the most thought-provoking rap idiom, but it's got a funky beat and you can mosh to it.")

Anyway. Now here's Kapone on the guest list at Club Breakthrough, thanks to an unlikely hip-hop kingmaker: Hollywood producer John Singleton, who enlisted the rapper's help to give "Hustle & Flow" its crunk.

Kapone wrote and produced two songs and performed a third for the film about an ineffectual Memphis pimp who desperately wants to transform himself into the crunkest rapper around.

And here is one of those loopy life-imitating-art footnotes that make publicists twitch with giddiness: The movie in which the lead has a ludicrous dream of, you know, becoming the next Ludacris, could also bring As-Seen-On-MTV-type stardom to Kapone himself, a southern-rap journeyman whose career has been spent scuffling in the shadows of the underground.

The parallel is not lost on Paul Stewart, the music supervisor for "Hustle & Flow."

"This is going to be an amazing boost for Al's career," Stewart says. "It's apropos for the film."

The movie, which opened Friday, tells the story of DJay (Terrence Howard), a low-grade pimp who harbors illusions of hip-hop greatness.

In his pursuit of crunk glory, DJay performs three songs -- two of them Kapone's: the urgent title track and the belligerent, plot-pivotal "Whoop That Trick."

Howard recorded his own vocals, and rather credibly so.

But Kapone doesn't cede the spotlight entirely: A festive scene in a skate-rink parking lot is set to the rapper's own recording, "Get Crunk, Get Buck" -- so named for the spasmodic and suddenly ubiquitous southern-rap subgenre that fuses seething, thugged-out lyrics with repetitive chants, foreboding bass lines and combustive beats. (The Memphis strain, of which Kapone is among the originators, is known as both "crunk" and "buck.")

All three Kapone compositions are featured on the "Hustle & Flow" soundtrack released earlier this month, with the maddeningly infectious and very much misogynistic "Whoop That Trick" a leading candidate to become the third single. (It's also the song whose titular refrain you're most likely to repeat for days -- mostly against your will. Don't say we didn't warn you, readers.)

There's also the surest measure of success: Kapone's "Hustle & Flow" songs are available as ringtones, yours for just $2.50 per at MTV.com.

The sudden exposure is heady stuff for an artist who has achieved little national notice since he began peddling his debut album, "Street Knowledge," in 1992.

By Kapone's estimates, he has sold "close to 100,000 copies" total of his four solo albums and a half-dozen compilations -- all of them released through Alkatraz Productions, an incorporated business with exactly one full-time employee: Alphonzo Bailey (Kapone's given name). Good work if you can get it, but hardly the stuff of crunk legend.

The most recent album from the kooky, self-proclaimed King of Crunk, Lil Jon, for instance, sold 363,000 copies in a single week last year -- plenty enough to elicit one of those absurd exclamations (Yeah!! What?!! Okay!!) that have come to define Lil Jon to the point that comedian Dave Chappelle now mocks him at every turn.

Not that Lil Jon cares. Chappelle gets the chuckles, but Jon's crunk gets the ladies buck naked. Seriously: Crunk is the soundtrack of choice at southern strip clubs. "Records start in the strip club," says Jason Geter, president of the Atlanta rap label Grand Hustle. "If the girls don't dance and get wild and the guys don't start throwing out a lot of money when your record comes on, it won't get played anywhere else."

Ah, the things to which Kapone can look foward.

"I've always done it on a small level with a little fan base," he says, speaking in an easy southern drawl that belies the aggressiveness of his recordings. "I'm hoping this movie gets me more love and attention."

The subtext, of course: more money!

Music supervisor Stewart says Kapone stands to make a small mint from the project, at least relative to his previous earnings. "For an independent artist, it's going to be a lot of money," Stewart says. "He should be seeing some real dough. But more importantly, it's going to open so many doors for him. MTV and all these people have become interested."

Kapone is calling his next album "True Underdog," in the same bootstrapping spirit of DJay, who figures he can shine if only he can get that one break.

Sort of like when Kapone just happened to call "Hustle & Flow's" writer-director Craig Brewer -- a past acquaintance -- at the very moment the Memphis filmmaker was expecting to hear from the popular local rap group Three 6 Mafia. Brewer told Kapone about this little screenplay he'd written, and he mentioned that Singleton was jetting in to meet with Three 6 -- but, hey, he said, since I'm down with your music, too, why don't you write a theme song, and I'll get you in with John, and, oh, by the way: He'll be here tomorrow.

"I had to do what I had to do," Kapone says.

He called Howard to talk about the actor's role, ruminated, and then scratched out a rough backing track and two lengthy verses that captured the movie's desperate, desirous spirit. By the time Singleton touched down the following day, Kapone had it in the bag. (The song, the job, the big break.)

"You always get the best music from the people who are the hungriest, and Al wrote something that was so dead-on," Stewart says. "He needed it. It meant so much to Al, and you could feel it in the music and lyrics."

Just consider the chorus: "Keep hustlin' -- it ain't over for me, no it ain't over for me / Keep flowin' -- I'm a step my game up and get what's comin to me."

It's Howard's performance, but Kapone's mantra.

"He had to make something happen, and he had to believe in himself even when ain't nobody else did -- and it represented not only myself, but a lot of artists out there trying to make it," Kapone says. "And I guess John was so impressed that he asked me if I'd play a few more songs. That's how he heard 'Whoop That Trick' and 'Get Crunk, Get Buck.' . . . I was just hoping to get that first song. But the one call ended up getting me three and a small acting role in the movie. So I can't complain right now."

Al Kapone, performing in Memphis, calls his crunk rap career a "blessing."

Rapper Al Kapone, left, with his family in his backstage trailer, has come a long way from selling copies of his debut album, 1992's "Street Knowledge," out of the trunk of his car.Above, Al Kapone holds forth at the AutoZone in his home town of Memphis. The 33-year-old rapper, left, seems poised for more success after writing and producing two songs and performing a third for producer John Singleton's acclaimed new film, "Hustle & Flow."