There's a strange sound in the pre-chorus of Britney Spears' "I Wanna Go"— a whistling sound, almost as if she had real lungs that could push air very quickly between her lips. That's impossible, of course. Britney is not a girl, not yet a distributed digital consciousness; ever since she established herself as a Britbot, she's been trying to turn herself more and more non-corporeal.

When "Hold It Against Me" came out, I discussed how her recorded and videographed personae were unraveling into bodilessness, and "I Wanna Go" is another step in that direction. Its "iiiiiiI-I-I" chorus makes her not just a machine, but a glitchy machine: its stutter is a digital stutter, breaking up a line longer than a human being's breath could reasonably sing. The effect is a pop variation on that bizarre breakdown from the "Hold It Against Me" video. (The Terminator imagery in the "I Wanna Go" video just underscores the cyborg themes of the arrangement.)

But then there's that whistle—the telltale sign of a person who breathes. It's an unusually biological sound in a song that's otherwise a glistening digital suit of armor. It's also a lot like whistling interludes that turned up in a couple of pop songs around the time Britney was born. One notable member of the "I Wanna Go" whistle family is Peter Gabriel's minor 1980 hit "Games Without Frontiers" (there's a "Brit" mentioned in its third line, but that has to have been a happy coincidence). The whistling in Gabriel's song and in Spears' have similar functions: they stand in for the idea of innocence and simplicity, to contrast with the complicated things grown-ups do. (It's not an accident that one of the first times we hear it in Britney's video, there's a baby who appears to be doing the whistling.)

Another song from 1980 with a similar whistle-riff is the Swiss art-punk band LiLiPUT's amazing B-side "Die Matrosen"—in their song, whistling makes up the entire chorus, a major-key release (if not quite the kind Britney's singing about) from the sour boinging of the verses. (In 1986, the American synth-pop band Book of Love recorded an electronic dance version of "Die Matrosen," which foregrounds the whistling even more.)

Of course, the similarities between all of those whistlers are compounded by the fact that nearly every whistler sounds almost exactly alike. There are exceptions—a handful of virtuosic whistlers like Brother Bones, whose "Rosetta" is as worthy of a listen as his famous 1948 version of "Sweet Georgia Brown"—but whistling is a great equalizer of even the most distinctive singers. The women of LiLiPUT whistle exactly like the men of XTC on another 1980 song, "Generals and Majors," for instance, even though you'd never mistake them for each other when they were singing.

And yet there seems to be something weirdly personal and human about whistling: the equation seems to run that everybody does it the same way, therefore anybody can do it, therefore the whistler is really like you. That's a dangerous syllogism, because signifying "genuineness" and "simplicity" provides cover to get away with all kinds of nefarious stuff.

See, for instance, this nifty 1967 performance of "I Was Kaiser Bill's Batman," a Top 20 pop earworm by Whistling Jack Smith. (That's not a Batman like the one who was the star of a TV show in that year, but in the sense of a soldier who acts as a personal aide to an officer.)

It's worth noting that the handsome young man in the military jacket was not the guy who was whistling on the recording, and that neither of them were named Jack Smith. That was a borrowed name—a play on an earlier generation's star singer, "Whispering" Jack Smith, who sang "Happy Days" in 1929.

The guy you see in the "Kaiser Bill's Batman" clip was a small-time pop singer who went by the name Coby Wells—that's "went by," because his real name was Billy Moeller—and had been hired to whistle-synch the record for promotional appearances. As for who's doing the actual whistling, the exact facts have been smudged by time, but one story goes that the main whistler on the record was record producer Noel Walker; another has it that the lead whistler was session musician John O'Neill. "I Was Kaiser Bill's Batman" wasn't even the song's original name—that was "Too Much Birdseed."

Are we supposed to believe that it's Britney whistling on "I Wanna Go," though? Maybe not—the only time in the video that we see her whistle-synching, she's got a look of feigned innocence on her face, as if she's trying to be the Spears of "Oops! I Did It Again." It's possible that there's no such thing as a genuinely guileless whistle, that the message that a human tweet really sends is always fake naiveté. If so, that may be the message Britney has been trying to send us for a long time.