Although his nearly singleminded fixation on sex has been a constant plumb line, R. Kelly’s catalog is remarkably diverse. Stylistically, over the course of a 20-year solo career he’s evolved with the times from New Jack Swing all the way to the Auto-Tune era and beyond, to the point that his latest album features a Future collaboration that could pass for Drake. Conceptually, too, the guy has covered a lot of ground; in recent years he’s delivered two straightforward traditionalist soul albums and dozens of bonkers Trapped In The Closet chapters. Kellz once released a double album with one disc full of steppin’ music and another dedicated to gospel songs. He’s done duets with everyone from Celine Dion to Jay-Z. His discography includes both the all-time classic inspirational ballad “I Believe I Can Fly” and “Real Talk,” a maniacally funny, progressively agitated one-sided phone call as R&B slow jam (and still my favorite R. Kelly song on most days, although “I’m A Flirt [Remix]” is stiff competition). And perhaps even more than R. Kelly has stayed in step with the times, the times have stayed in step with R. Kelly. He’s a pioneer of explicitness, continuously pushing the boundaries of how openly freaky pop music can be. His influence on urban music is widespread and unmistakable, from the radio dominance of Trey Songz to the underground sexcapades of Ty Dolla $ign. Kellz was born with a voice that can conjure the elemental life forces that hold this universe together, and he’s used it to do just about everything an R&B singer can do.

Yet there’s a very specific and narrow public conception of what an R. Kelly album is like. Basically, it involves Kellz singing about sex in every possible scenario (at the club, in the kitchen, in space, etc.), using every possible metaphor (a key in the ignition, animals in the zoo, yodeling, etc.) or dispensing with metaphors altogether in favor of something blunt like “Girl, you make me want to get you pregnant.” It’s nonstop sensuality bordering on hilarity, and it’s become his signature move to the point that in recent interviews like this one he’s taken to writing bedroom goofs about subjects such as dolphins and Italian hero sandwiches on the spot. A significant portion of his audience expects and even demands that sort of thing from an R. Kelly album these days, even as he continues to prove he can pull off just about any of the many endeavors he attempts. Black Panties, though, is exactly the R. Kelly album we imagine. It meets the public’s expectations to a fault: a coitus-crazed romp in which Kellz takes his passion for making love every which way to X-rated cartoonish heights.

Let there be no doubt that there’s canonical material here for those of us who delight in hearing R. Kelly sing colorfully about sex almost as much as R. Kelly delights in sex itself. Early chatter seems focused first and foremost on “Marry The Pussy,” in which Kellz expresses his desire to wed a vagina (but, crucially, a vagina that will bring along other vaginas when he feels like it). He refers to the pussy as his best friend and life companion and passionately sings, “This is a sex proposal.” It’s as preposterous as you imagine and nearly as marvelous, though the way he neglects the rest of the woman attached to that extra-special body part seems out of character for Kellz. Other highlights include “Cookie,” which matches aggressive synth rumble and ominous minor chords with proclamations like “You gonna wanna claim this dick” and “I love to lick the middle like an Oreo” (yes, he also calls himself a cookie monster) and “Throw Money On You,” which is more literal. On the ineffable yet very F-able “Genius,” he calls himself a sex genius, and who’s to argue?

The trouble with Black Panties is that so much of it fails to reflect that genius. Aside from a brief stretch in the middle of the album that tackles other topics such as R. Kelly’s personal history (“My Story”), his buddies (“Right Back”), his money (“Spend That”), and his haters (“Shut Up”), the 17-song tracklist is all sex all the time, which is obviously not a problem in and of itself. But while the first half is frequently rapturous, as the album begins to sprawl to impossible lengths rivaling any set of king-size bedsheets, the songs start to run together, resembling some lesser talent’s impression of the R. Kelly chocolate factory. Behold a masterful lothario on autopilot: “Crazy Sex” is about crazy sex. “Physical” is about getting physical, you know, in bed. “Every Position” is about how Kellz wants to have sex in every position. Are we sure he didn’t write these spontaneously during interviews too? Meanwhile, he’s assembled every sex-crazed collaborator you could want on an R. Kelly album in 2013, including Ludacris, 2 Chainz, Future, Juicy J, Migos, and Kelly Rowland, lest we forget she sang on the sumptuous Mike Will Made-It production “Kisses Down Low.” Yet so many of those guests are squandered, whether that’s Rowland and Kellz engaging in tired sex-as-drugs banter on “All The Way,” or turning the lone contribution from ratchet producer extraordinaire DJ Mustard into one of the album’s few songs not about having extremely ratchet sexual relations. Talk about a missed opportunity!

Are the best parts of Black Panties enough to render it the most notable album of a slow December release week? With all due respect to 7 Days Of Funk, yes. R. Kelly can rightfully call himself the king of R&B because any track he lends his majestic voice to is worth a listen, especially considering we almost lost that voice for good. Kelly addresses his 2012 throat surgery and other troubles directly on “Shut Up,” and his claims are pretty persuasive: “Now seriously, after all these hits and melodies and memories, you compare me to someone else! OMG! Well no offense to the other artists, but come on dog, let’s be honest, how many babies have been made of me? OMG!” How many babies, indeed? Like any legendary musician, R. Kelly can’t just coast and expect to inspire the same hosannas he did with the likes of “Bump & Grind” or “Echo.” But for all the coasting on Black Panties, the album also presents a generous bounty of reminders that we’ve come to associate this kind of song with R. Kelly for good reason: Nobody is freakier, funnier, or more powerfully evocative.

Black Panties is out now via RCA.

Other albums of note this week:
•Dam-Funk & Snoopzilla’s hazy George Clinton homage 7 Days Of Funk.
•Raconteurs member Brendan Benson’s latest alt-pop opus You Were Right.
•Actor-turned-rapper Childish Gambino’s confrontational Because The Internet.
•Guerilla Toss’ spazzy noise-punk debut Gay Disco.
•Finnish goth post-punks Beastmilk’s darkly furious Climax.
•The CD release of Rhye singer Milosh’s sleek and moody love song composite Jetlag.