"Black Sweat" was a nervy modernization of the stripped-down funk that once propelled "Kiss," the kind of song that frustrated as much as it delighted. Why wasn't Prince always this great?

Maybe because he could craft electro-funk jams in his sleep. Maybe because this genre-smashing iconoclast simply didn't wanted to be fenced in. Maybe because "Black Sweat," released as the second single from 2006's 3121, found Prince hinting at a youthful lewdness that he'd been deftly skirting since becoming a Jehovah's Witness. (You could easily picture this song on The Black Album when Prince, returning to a Camille-style falsetto, squeals out lines like "you'll be screaming like a white lady when I count to three.")

Maybe it was all of that, as he relays a stripper's lament over a strikingly stark drum machine's cadence and an eerie synth line straight out of the Ohio Players' "Funky Worm." (As with "When Doves Cry," any bass has been deleted from the mix.)

The song's origins date back to the summer of 2004, at least, when Prince began playing "Black Sweat" during the acoustic segment of his tour in support of Musicology. He subsequently spent a few days at Paisley Park studios, in between dates, and likely did initial tracking for "Black Sweat" at that time, according PrinceVault.

If it started out in the same acoustic manner, something very funky clearly happened along the way. Something so funky, even Prince's protagonist is moved. She apparently doesn't initially feel up to entertaining the clientele, but (of course) finds this groove simply too irresistible.

Prince didn't have the same luck with Billboard, where "Black Sweat" somehow stalled out at No. 60 on the Hot 100. Still, buzz from this familiar, but not too familiar sound helped 3121 debut at the top of the album chart, earning Prince multiple Grammy nominations along the way. The distinctive, Sanaa Hamri-directed black-and-white video, which featured real-life dancer Celestina Aladekoba, was also nominated for an MTV Video Music Award for best cinematography.

Yet, for all of the ways this felt like a throwback moment – right down to that heralded chart resurgence – Prince still clung to a married man's newfound sensibility, if you listened carefully enough. Aladekoba's character, after all, appears to be monogamous. "Don't want to turn nobody on," Prince coos, "'less it's you."

More From Ultimate Prince