At one point during this 2003 Argentinean documentary a musician describes Buenos Aires as the real city that never sleeps (with apologies to Sinatra), a characterization that explains why it spawned the tango and, along with it, some of the most sensual music ever made. Filmmaker Mercedes Garcia Guevara provides a historical overview of the dance, with arresting performance footage of the great singer Carlos Gardel, but she’s more interested in explaining tango’s deep connection with the city. Among the other inspired performers are the ensembles La Chicana and Los Munecos and singers Fernando Otero and Dolores Sola; the latter is accompanied by songwriter-guitarist Acho Estel, whose tunes prove that tango continues to evolve. 98 min.