Family car rides being what they are, and commercial radio being what it is, I’ve been hearing a lot of love songs lately. Out of the speakers they come, in heavy rotation, zooming at my skull in little Frisbees of processed desire. Every time that you get undressed / I hear symphonies in my head. That’s the sugary falsetto of Jason Derulo.

Then there’s Ariana Grande’s “Love Me Harder,” a cushioned club pulse quaking the inner walls: And if in the moment I bite my lip / Baby, in that moment you’ll know this is / Something bigger than us and beyond bliss. Beyond bliss? Symphonies in the head? Are these love songs or sex songs or some kind of new religion? All three, evidently. Lust chimes in Derulo’s molars. Grande struts and flutters. Ooh, ooh, we’re in the moment. You and me, me and you. Transcendence is the promise, or the commodity—escape from the self via big, jangling booty. Surface-to-air sensuality, fornication on the heights. Spritz it with the eros of late late capitalism, that fizzing, unappeasable need, and you’ve got yourself a hit.

Not that all the love songs on the radio are so saucy-celestial. Taylor Swift’s “Blank Space” is platonically chaste by comparison (I’ve got a blank space, baby / And I’ll write your name). And “Habits (Stay High),” the sleeper hit by Tove Lo, is sorrowful and world-darkened: You’re gone and I gotta stay / High all the time / To keep you off my mind. (The first time I heard this song, driving along, I started shouting. “Now this is a bit more like it! Are you hearing this? This is fantastic. This is real. She’s saying that she’s doing drugs because her heart is broken!”) But the beautiful confusion of soul and body, the prickle in the ether and the prickle in the underpants, is—according to Ted Gioia’s fascinating new volume, Love Songs: The Hidden History—intrinsic to the genre. “In a very real sense,” Gioia writes, “our modern discourse of love, even at its most carnal, is constructed on a foundation of spiritual aspirations and metaphysical paradigms.” Go, cat, go!

Gioia has constructed a mind-expanding, deep-focus piece of scholarship here, certainly the first book to relate, longitudinally as it were, the West African Wolof people’s “dance of the amorous mallard, in which a couple emulate the mating of ducks to the accompaniment of a song with explicit lyrics,” to Gang of Four’s “Love Like Anthrax.” A joke in Chapter 1 nearly derailed me: “Mick Jagger has allegedly slept with more than 4,000 women. So much for getting no satisfaction!” (Which is not just feeble but wrong, surely, the point of the song being that you can sleep with 40,000 women, or 400,000, and still not be satisfied. See above: fizzing, unappeasable need.)

But I pressed on, and I was rewarded. The genesis of the love song would seem to lie somewhere in the fertility rites of the ancient world: the Sumerians, for example, had a number of hymns/love songs to celebrate the sacred marriage of the king (human) to the goddess (immortal), these nuptials being conducive to a rich harvest, cultural plenitude, satellite dishes for everyone, and so on. It doesn’t take long, however, for the songwriters to start sounding like people we know. A very handsome gentleman / Waited for me in the lane; I am sorry I did not go with him. This early draft of The Smiths’ “This Charming Man” (When in this charming car / This charming man / Why pamper life’s complexities / When the leather runs smooth on the passenger seat?) was apparently composed in China somewhere between 1000 and 600 B.C.

Gioia touches in passing upon the love song’s evolutionary brief—that is, to encourage men and women down the ages to have sex with each other. (Even today, he suggests, when I’m listening to “Love Me Harder” in the car, I am being “enticed into vulnerability for the good of the species.”) But he’s more interested in the evolution of the love song itself—or rather its sinuous passage through time, because one of his arguments is that the basic elements have been there from the beginning. It’s hard not to agree with him, really, when Egyptologists are finding amid the pottery shards and crumbling papyri lines like If only I were the laundryman … / Then I’d rub my body with her cast-off garments. Gioia credits women with the greatest breakthroughs in love-song self-expression: “Women were the innovators and men the disseminators”— which sounds anatomically correct, at least. Love shook my senses, / Like wind crashing on the mountain oaks. That’s Sappho, or the composite forensic entity known as Sappho, sounding like Kelly Clarkson.

Fear of the love song, of its emotional extremity, has been a historical constant.

Fear of the love song, of its emotional extremity, has been a historical constant, Gioia says. The Romans defended themselves with jadedness and sex-obsession: their love songs were rather trivial. The early medieval Christians were nearly phobic: the very presence of love songs in their culture has to be inferred from the amount of denunciations such songs received from the pulpit. But as the priests volleyed and thundered, the love song was approaching one of its great flowerings, in the upward-flying utterances of those strolling love-loonies, the troubadours. Lean out the window, golden hair; my heart is in bondage and my lute is on fire.

This is where Gioia’s book achieves intellectual liftoff, high learning combining with high imagination as he traces the courtly trope of romantic enslavement back to the physically enslaved female performers of Muslim Iberia, shimmying before their caliphs: Sire, you have burdened me with sleeplessness / And it is you who taught my love ecstasy and passion. “This servile stance,” this wacko celebration of ownership and enthrallment, for Gioia, is the love song: “Lovers humbly serve the beloved in romantic music because the originators of these kinds of songs were literally slaves and servants.” Female musicians and marginal types, indentured or enchained, have carried the torch through the centuries.

Gioia leaves uninvestigated my own preferred variation on the enslaved love song: the song of addiction, in which love is like a drug habit, or a habit is like love, or it’s all the same thing. In this slender but deep subgenre we find The Stranglers’ “Golden Brown,” The La’s “There She Goes” (There she goes again / Racing through my brain … / Pulsing through my veins), Roxy Music’s “Love Is the Drug,” The Gun Club’s “She’s Like Heroin to Me,” and indeed Tove Lo’s “Habits”: chemically wistful, spangled with neurological damage.

Gioia’s love songs go on, through opera, cabaret, the blues, and the Summer of Love—when eros was briefly absorbed by, or confused with, agape—all the way to Miley Cyrus at the 2013 MTV Video Music Awards, “bent over like a female cat in heat.” Gioia writes brilliantly about the lilt of irony in Frank Sinatra’s voice, through which he achieved “both an acceptance of vulnerability to the feeling-state of the song, and a macho assertion of independence from its jurisdiction.” The love song, “slave song style,” arises in subversion, is assimilated, goes undergound, and rises again in a new form. I lack the scholarly chops to assess Gioia’s love-song-as-song-of-the-outsider theory qua theory—but I don’t need to, because a couple of months ago I saw it in action.

I was at a rally on Boston Common. The cause was just, the people were righteous, there was oratory and there were sing-alongs, and for an apolitical lurker-loiterer I was doing okay—I was more or less present. Then the crowd started up with “We Shall Overcome,” and I was obliged to remove myself. As I sloped toward the subway, I passed a lone street performer, scrubbing his way through Donovan’s “Colours.” Mellow is the feeling that I get / When I see her, mm-hmm / When I see her, uh-huh.

Behind me the weary strains of “We Shall Overcome” were still audible, in all their dismal stoicism. But here was this busker, this jongleur—unattended, unremunerated, in the pigeon-gray precincts of downtown Boston—singing about the color of his true love’s hair in the morning. That’s the time, that’s the time / I love the best. It was private and quietly rapturous, a wild affront to the prevailing reality. It seemed to me, at that moment, the most radical form of dissent possible. It was a love song.