Patti Cake$

Wow, Meat Loaf really let himself go.

The title character in “Patti Cake$,” one Patricia Dombrowski (Danielle Macdonald), is a portly white New Jersey girl who aspires to be a rapper. She’s quite good at it, spitting rhymes as intricate and vulgar as anyone’s; she just needs her big chance. She lives in a dumpy white-trash town with her cigarette-hacking grandmother (Cathy Moriarty) and brassy, jealous mother, Barb (Bridget Everett), who gave up her own dreams of rock stardom when Patti came along. They live hardscrabble lives, paycheck to paycheck. When Patti tells Nana a dirty limerick, Nana hack-laughs and says, “Suck on that, Robert Frost!” Charming family.

Though it sounds like the setup for a laugh-at-the-buffoons comedy, writer-director Geremy [sic] Jasper presents it as a legitimate dramedy about an underdog determinedly pursuing her dreams. It almost works. Jasper quickly gets us past the novelty of a rapper looking like Patti — it’s not a one-joke movie, and that’s not the joke — but his treatment of the formula is shallow and glib, with contrived conflicts and convenient climaxes. The details by which Patti meets her idol, a Jay-Z-like rapper named O-Z (Sahr Ngaujah), and then encounters him again later should never have made it past the first draft in a script not intended as a parody.

Macdonald’s performance as both a rapper and an actress is impressive and sometimes endearing, and the film is best when it stays light: Patti freestyling with her Indian-American friend Jheri (Siddharth Dhananjay) on the public-address microphone at the pharmacy where he works; the two of them getting producer help from a taciturn African-American speed-metal enthusiast named Basterd (Mamoudou Athie) who lives in a shack in the woods (and is also sort of a “magical Negro” figure, appearing out of nowhere to show Patti the way); Patti dominating in a rap battle against a cocky Eminem wannabe (McCaul Lombardi) who goes right for the fat jokes and lives to regret it. The inspiration is faux and the repairing of Patti and Barb’s mother-daughter relationship is forced, but the rest of “Patti Cake$” is a¢¢eptable.

B- (1 hr., 48 min.; R, pervasive profanity, some vulgar sexual dialogue.)