What works on stage or CD doesn't always crossover to the screen. Case in point: Curtis '50 Cent' Jackson, the emotional black hole at the center of 'Get Rich or Die Tryin,'' a film based loosely on the superstar rapper's life.

By now, of course, the legend of 50 Cent is about as famous, and ubiquitous, as Rosa Parks and her little incident on a cross-town bus. The Queens-born Jackson lost a mother to the drug trade, became a dealer himself, served time in the slammer, and was shot nine times in an assault that nearly took his life. All of this is included in the film, which wants to be a combination of 'New Jack City' and '8 Mile,' but instead comes off as an all-too-familiar combination of an up by the bootstraps showbiz biography and 'Godfather'-like rip-off.

Don't blame director Jim Sheridan. He may be Irish, but there's no doubt Sheridan knows his ghettoes, even though the ones he usually makes films about (like 'The Boxer') happen to be in Northern Ireland. No, Sheridan has the gangsta atmosphere down just fine, and he has paced some sequences (an attempted murder in a prison shower, the effort to save Marcus's life -- 50's character -- after he's shot) with startling immediacy.

Yet even this cagy veteran can't save the film from its overstuffed screenplay and a lead performer who has the charisma of a blank audio cassette (it doesn't help that there's not one cut on the soundtrack to equal the power and passion of Eminem's Oscar-winning 'Lose Yourself'). Writer Terence Winter has filled his story with so many killings, confrontations, double crosses and minor characters at times you need a blueprint to figure out who's messing with who. It's all pretty derivative stuff, as if you're watching an endless loop in which 'Scarface' and 'Menace II Society' are spliced together, creating a lot of sound and fury signifying -- nothing.

And then there's Mr. Jackson. We certainly know by now that plenty of rappers can act - can you say Ice Cube, LL Cool J, Mos Def, Ludacris and the late Tupac? -- but 50 isn't one of them. His repertoire of expressions encompasses menacing or clueless, nothing more, and he has a disturbing tendency to bare his rather large teeth when attempting to express emotion.

Worse, Jackson has been surrounded by a cast of actors who make him look like the amateur he truly is. The supremely talented Terrence Howard ('Hustle and Flow') plays Bama, Marcus's prison buddy turned manager. Bill Duke, who's practically patented Black Godfather roles, is Levar, king of the Queens drug trade. And Adewale Akinnuoye-Agbaje, best known as the scary con Adebisi on HBO's 'Oz' and now Mr. Eko on ABC's 'Lost' is Majestic, the mentor who turns on Marcus and becomes his worst enemy and 'Antwone Fisher's' and 'Baadasssss's' Joy Bryant plays Marcus's love interest.

There's a good, if cliched, story hidden in here somewhere. Certainly the narrative of a basically decent kid from the streets trying to shed his thug life and become a responsible adult has been told before, but there's no reason why it can't be told again. The problem, however, is that even though 'Get Rich or Die Tryin' is Jackson's story, the performer's inability to show some sort of interior life keeps the audience at a distance from his character. Without this connection, the film ends up being nothing more than a slick, and ultimately empty, moral tale.