One of the best moments in pop music is the “they said what?” moment. The incredulous shiver of registering that the words brushing over your ears are so filthy — so deliciously, improbably obscene — that you can’t quite believe they’ve been allowed.

Listening to “Captain Hook” by Houston rapper Megan Thee Stallion (the name is slang for a tall, hot girl), I snag on a lyric that sounds like something outrageous, replay it a few times to confirm, and find out that yes she did say: “I like a dick with a little bit of curve/Hit this pussy with an uppercut/Call that nigga Captain Hook.”

And before there was Megan singing the praises of a man who can catch you just right, there was the time I was doing Nicki Minaj’s “Super Bass” at karaoke with a friend and we both clocked the line “When he make it drip, drip, kiss him on the lip, lip” right before he (my friend Dave does the rapping) had to deliver it.

And before that, there was the time when I was listening to PJ Harvey’s stately, aggressive cover of “Wang Dang Doodle” after a childhood of hearing the Koko Taylor version, and suddenly realised that the “fish scent” and “snuff juice” at this party might be something else entirely.

I like my pop smut best when it comes from women. The Howlin’ Wolf recording of “Wang Dang Doodle” sounds rinkidink and benign in comparison with Taylor, whose warm roar of vocal is maybe an invitation and maybe a warning that whatever is about to go down at the Union Hall is something you might or might not enjoy, but that will definitely leave you changed the morning after.

Maybe I’m just a big hypocrite, or maybe it’s the pleasure of breaking the still-just-about-standing taboo around women stating what they like and what they want, or maybe it’s that male sexuality announced straight-up often comes over as brutishness.

It’s definitely hard to imagine Frankie Goes to Hollywood’s “Relax” being so enormous on its 1984 release if the invitation to “hit me with your laser beam” had come from a singer less impishly charismatic than Holly Johnson, who edges (fittingly) right up to and then over the limits of your disbelief that he’s getting away with this.

If you’re going to ban records for sounding horny you might as well go full Taliban

Not that they did get away with it, exactly: despite the band’s implausible claims that the song was actually about motivation and not oral sex, the BBC elected to ban it in a spasm of purity that did nothing to hurt the song’s popularity, and everything to make the BBC look stupid.

One of the reasons this made the BBC look stupid is that all pop music, really, is about sex. If you’re going to ban records for sounding horny you might as well just go full Taliban about it.

So insistent is the dirtiness on the soul of pop, people hear it even when it isn’t there: the Kingsmen’s “Louie Louie” launched a two-year obscenity investigation by the FBI, convinced that somewhere in Jack Ely’s garbled vocal, there must be some incredible depravity. There isn’t — the actual words are bland to the point of boring, as any version with half-decent diction goes to prove.

But it doesn’t matter what Ely sings. What you hear is what he means, and whether it’s deliberate on his part or he was merely an impersonal conduit for the force of rock’n’roll in the moment of recording, it’s there.

In a letter to J. Edgar Hoover in 1965, a member of the Flint Junior Woman’s Club pointed out that the lyrics were irrelevant when “every teenager in the country ‘heard’ the obscene not the copywritten [sic] lyric,” demonstrating that haters are often better critics of the thing they hate than its defenders are.

The feeling of disorder is right there in pop music because of its origins. Rhythm and blues was filtered into rock’n’roll, and then polished up again to become pop: however much the music was bowdlerised, a conservative-minded listener could always pick out the riot within, and this is particularly true in the US, where the translation of black music to fit the sensibilities of a more prim white audience hinted at a kind of miscegenation that would upset the most basic fabric of a society built on racial hierarchy.

Pop is a form which carries its profane origins around inside it

So it’s not that pop music is getting dirtier, although the BBC censors who tried to choke “Relax” would probably cough up a kidney if they ever heard “Captain Hook”. It’s that pop is a form which carries its profane origins around inside it, and the oldest stuff is just as deliciously shocking. I was listening to “Eagles on a Half” by Geeshie Wiley, one of the earliest recorded blues songs, when I hit the line “squat low, papa, let your mama see/I want to see that old business, keeps on worrying me.” And it only took me a few FBI-style listens to determine that yes, like Megan, she was singing about a dick.