It is Saturday night, and somewhere in the Imperial City two performers sweat for acclaim: Miguelito on the guitar, Ginette in a trance. Their flamenco performances are full of yearning and frustration, as befits any display of repressed sensuality in Andalucia. I grew up there, in Iberia's south, at a time when there might have been bikinis but there was no kissing in public. Any display of unusual ambition attracted attention, sometimes from authority. And this is flamenco's genesis. The desire to titillate, unallowed, unalloyed, hidden in caves, sprung out for the well-heeled to get their own dead senses lit. People of faraway origin and unknown virtue: these are who you wish to see in the dark, stomping around the fire, promising something no money can buy, sex without a contract. Times have changed of course. There is porn on your iPhone, free. But in the flamenco cavern, you can still wonder at the possibilities you will never know.