With a pulsing,angular reggaeton soundtrack from Chilean-American composer Nicolas Jaar,the film throbs and leaps rather than walks. If the music video was ever going to produce anything of lasting artistic value,a sense of connection to the way some people now think and feel,this film might well be it. MTV with depth. Who’d’a thought?

It’s partly about generations. Ema behaves as if there are no limits to what she might be,but this does not save her from woe. She and her husband,Gaston (Gael Garcia Bernal),have broken up after a tragedy involving their adopted son. They gave him back. Ema is haunted by the guilt;Gaston thinks choreography will save him.

The film’s location is important. Valparaiso is Chile’s main port,a vibrant hilly metropolis with an intense street life. Ema and her pals come out at night like moths,dancing and cruising and hooking up at will. Reggaeton is the most important contemporary music form in Latin America,hence its primacy in the movie. The dance is a form of rebellion as well as refuge.

In Larrain’s hands,this story is a duet between him and a younger generation,through the beautiful and mercurial Di Girolamo. In that,there is a sense of filmic tradition — a director and his muse — except that Ema would reject such a role. She wants to be free of all the old concepts. I think Larrain envies that freedom and spontaneity. The movie is his love letter to the generation coming up behind him,the one for whom Pinochet is not a living memory.