Back in the late ’90s, fire-breathing battle rapper Rah Digga was the only sidekick in Busta Rhymes’ Flipmode Squad who could outroar the dungeon dragon himself. A decade after her 2000 debut, Dirty Harriet, she’s still going full throttle. “Who’s gonna check me, boo? / Not you!” she shouts on Classic, a set well-stocked with energy blasts like “Back It Up” and “This Ain’t No Lil’ Kid Rap,” all produced by New York head-nod specialist Nottz. Save for “Viral,” where she addresses some online gossip chatter, Rah Digga doesn’t show much patience for introspection. But what Classic lacks in subtlety, it makes up in rowdy exultation.