Say the word flamenco and most people picture the same things: a dancer in a red dress, heels hammering the floor, a guitar strummed to a blur — in short, Spanish passion. But before we get to the glamour, there is something that has to come first. The people who made flamenco spent centuries being treated, by that same Spain, as barely human.

Flamenco was born in Andalusia, in the far south of the country. Around the fifteenth century a migrant people who had travelled from the direction of India settled there. In Spain they are called Gitanos. English long rendered the word as 'Gypsy,' but that is an outsiders' label, and because it carries a slur, careful writers now avoid it.

The Gitanos lived on the margins of Spanish society for generations. They were forbidden to settle, forbidden their language, at times rounded up en masse. Stripped of land and property, what remained to them were the trades a person can carry in their own body: metalwork, horse-dealing, and song and dance. Flamenco grew out of that last one.

So early flamenco had no audience. No stage. There was only the voice — the cante — sung in kitchens and courtyards, at the forge, in poor taverns, among family and no one else. Often there was not even a guitar, just hand-claps and a melody wrenched from the throat. What was sung about was hunger, prison, a dead child, love that went unanswered — their own lives, in other words.

This matters. The root of flamenco is not the bright word 'passion' but something closer to pain. The oldest and heaviest style of song is called cante jondo, the 'deep song' — a lament dragged up from the pit of the stomach. Tell the story of flamenco without that memory of pain and you have thrown away half of it.

The family music began to go public in the mid-nineteenth century. Across Andalusia's cities, venues called cafés cantantes opened one after another, staging song and dance for paying customers. Gitano and non-Gitano singers, dancers, and guitarists performed for money. It was the moment flamenco first became a product.

That move onto the stage had two faces. On one side, guitar accompaniment was refined, song forms were codified, and dance was polished into spectacle — flamenco was established as an art. On the other, a music of pain had its corners rounded off into entertainment made to please a crowd.

Into the twentieth century the process accelerated. In 1922 the poet Federico García Lorca and the composer Manuel de Falla organized a Cante Jondo contest in Granada, trying to protect the 'deep song' before it was watered down. There is an irony there: the very fact that a rescue campaign was needed proved flamenco had already begun to change.

Then, in the mid-twentieth century, under the Franco dictatorship, flamenco was decisively turned into the face of Spain. The regime marketed bullfighting and flamenco as the nation's image for tourists. But what got sold was a flamenco with its dangerous thorns pulled out — bright, legible, easy.

The emblem of this tidied-up sound is copla, a song style that grew up alongside flamenco. Copla is theatrical narrative song: it keeps flamenco's vocal turns but adds an orchestra and smooths everything into something anyone can enjoy. The track below, Concha Piquer's 1936 recording 'Ojos Verdes' (Green Eyes), is a landmark of the form. Listen to that grand, theatrical delivery and you can measure how far this has travelled from the cry in a Gitano kitchen. Flamenco was becoming beloved by the nation and, at the same time, being eased a little further from the pain at its root.

Made into a tourist souvenir and sanded smooth — against that, the later twentieth century saw a tension run through the flamenco world that might be called the purity war. What is real flamenco? Can only those with Gitano blood truly sing it? How faithfully must the traditional forms be kept? The moment you mix something foreign in, is it still flamenco at all?

Into the dead center of that argument walked two geniuses: the guitarist Paco de Lucía and the singer Camarón de la Isla. The two often recorded together, and between them they split the history of flamenco in half.

Paco de Lucía rewrote tradition first through sheer technique. He took the guitar, which had been mere accompaniment to the voice, and promoted it to a soloist worth listening to on its own. His 1973 'Entre Dos Aguas' (Between Two Waters) is the emblem of that shift. Said to have been improvised partly to fill out the running time of a record, the piece lays a rumba rhythm under bass and bongos and, on flamenco guitar alone, makes people dance and swoon. Flamenco with no singing, streamed around the world — that in itself was an event. Paco would go on to play with the jazz musicians Chick Corea and John McLaughlin, stepping across the border between flamenco and jazz without a second thought.

The other man, the singer Camarón de la Isla, blew up the heart of flamenco — the singing itself — from the inside. Born into a Gitano family and regarded as the rightful heir to the traditional cante, he was, to the guardians of purity, the very embodiment of their ideal. And he deliberately betrayed it. On his 1979 album 'La Leyenda del Tiempo' (The Legend of Time) he brought in electric instruments, jazz- and rock-inflected arrangements, and the poetry of Lorca and Omar Khayyam.

When it came out, older purist fans were furious. There is even a story that flamenco shops piled up with returned copies. To the defenders of purity this was plain treachery. But the young went wild for it. Today that single record is regarded as the monument that carried flamenco into its next era. What the guardians of purity condemned as 'no longer flamenco' turned out to be exactly what kept flamenco alive. In the track below you can hear the weight of the deep song and the texture of a wholly new sound coexisting inside a single throat.

At the same moment, commercialization was reaching its own extreme. The Gipsy Kings, a Gitano band of Spanish descent born and raised in southern France, scored a global hit with rumba flamenca, a sunny pop offshoot of flamenco. Their 1987 'Bamboleo' became shorthand for the 'Spanish-sounding' music you hear in adverts and at parties everywhere. To the purity camp this is the finished form of the tourist souvenir. And yet it is also true that this bright, open sound carried the word flamenco to the whole world.

So, whose flamenco is it? The Gitanos who bled it into being, the state that hung it on Spain's face, the purists who guarded its forms, or the geniuses who broke those forms and, in breaking them, saved it? The honest answer is that flamenco has never belonged to any single owner. It has always been something wrenched from the throat under pressure — and the pressure, over and over, is what has kept it alive.