Relevance: It’s what every musician strives for. But how to stay hip when you’ve been in the game for 20 years? Much less the club-music game, which is both fickle and niche.

Drag superstar RuPaul’s recording career could have walked quietly off into the kitsch sunset after 1992’s “Supermodel of the World.” Its hit single “Supermodel (You Better Work)” would have endured as a retro club classic.

Instead, he’s come to reign over a self-made gay-media empire constructed around “RuPaul’s Drag Race.” Contestants lip-sync to his singles, all of which are available on iTunes — a fact he repeats often.

He also knows the value of a guest star. Ru’s new single and video, “Peanut Butter,” features New Orleans Queen of Bounce, Big Freedia. A summary: Men in underpants dropping it low; Freedia providing booty beats and freak-out chorus; RuPaul demurely declaring, “Must be jelly cause jam don’t shake.”

Freedia is not a drag queen; she’s a transgender rapper getting her own name. This merging of gay icons and musical styles creates a hugely over-the-top single — which is what the young’uns want in any genre.