Carlos Saura is 80, though he looks 60. With a lived-in face and straggly grey hair, he resembles a rebel professor on a 1970s campus. He’s garrulous and speaks a rolling, recklessly elided Spanish. He’s had seven children by four women, one of them Geraldine Chaplin, the actor-clown’s fourth child. This old man from Aragon—he was born in Huesca—has a self-evident lust for life.

Rodrigo y Gabriela’s flamenco gymnastics have gained such a reputation over the past couple of years, it’s been suggested that watching them is like being at a circus. Ever since these two Mexican buskers came over to Europe and started dazzling with their near impossible heavy-metal-on-nylon-strings routine, audiences have been left drop-jawed at their speed and exuberance. But, unless Rod and Gab want to end up as a novelty, they know their current routine can only take them so far. Their solution? A slight change of direction and a bunch of musicians called C.U.B.A.

Flamenco is a fervently political dance language, riddled with subversion of class and gender rankings, honouring old people, hallowing sexual prowess, relishing mavericks, and yet commanding a special symbolic force when it's disciplined into a cuerpo de baile.

Two hundred years ago in Durham taverns you could find men in wooden clogs clattering on the tables, with their mates pressing their ears to the underside of the surface. Meanwhile, at the other end of the world, African slaves with bare feet were shuffling on dirt with metal bottle caps held between their toes. Now picture a Mediterranean gypsy dancing of sorrow and pain with swirling shawls and angrily pounding heels. Three quite different scenes, different places, different eras, but all rooted in one human impulse, common the world over.

In the age of Skype and no-frills budget travel, frontiers barely exist – at least if you’re not an immigrant or refugee. World music is as much about boundary-breaking and fusion these days as it is about discovering the unsullied treasures of what UNESCO calls the "intangible heritage". Contemporary global sounds can feel like an opportunistic marriage between musicians who have little in common, or else a more appropriate union with some basis in cultural kinship or history.

With an expensive-looking camera in one hand and a cigarette in the other, Spanish singer Buika’s sepia-tinted CD cover photo is making eyes at me, making it hard for me to think of a bad word to say about this career-so-far summation. I don’t know about the camera, but that cigarette may well be a valuable tool in Buika’s trade, helping her voice to achieve that sandpaper surface texture. It’s a voice which perfectly contrasts with the occasionally overly tasteful piano-led arrangements which grace material which embraces flamenco and jazz as well as R&B and Latin dance rhythms.

One thing became clearer to me last night – just how much Steve Reich has borrowed from world music in his compositions – we had the flamenco-tinged Clapping, Electric Counterpoint, using Central African guitar lines, and Music for 18 Musicians, a mix of West African rhythms, Indonesian gamelan and other elements. It was also clear how much a sold-out late-night Prom audience had taken this music to their hearts, nearly 40 years after some of it was written. It still sounds fresh and, rather than being mindlessly repetitive, most of it shimmers away.

There are gifted dancers and there are creatures of the stage. You know the difference immediately. The latter have something shamanic about them, ageless at any age, almost eccentric in their power. Eva Yerbabuena is one of those very rare creatures, to whom I succumb as helplessly as a rabbit in front of a cobra.

Every February the Sadler’s Wells flamenco festival summons the illusion of Spanish sun onto our chilled, grateful backs - this year singers are getting almost as much prominence as dancers. But what sun, I ask, at Estrella Morente’s dark, often remote evening, opening the fortnight last night? (And why, still, after years of urgent requests, no subtitles for these pungently melodramatic lyrics?)

I am far from the first - and in very good company - to worry about the over-commercialisation of flamenco. As far back as in 1922 Manuel de Falla and Federico Garcia Lorca, respectively Spain’s greatest composer and poet of the time, decided to organise a singing competition in Granada in which only singers from the villages were allowed to enter. The polished, preening urban stars of the Café Cantantes were ineligible. My resistance to the genre was partly to do with the Gypsy Kings, amusing enough when you first heard them, but irritating beyond words when heard for years in every wine bar in the world.