He's a small man, wiry, bespectacled. His three band members - guitarist Pedro Sá, bassist Ricardo Dias Gomes, percussionist Marcelo Callado - must each be about a third his age: a case of three pupils and a professor? Behind them is a screen which, through this one-and-a-half-hour set, will flash up clips of Brazilian seascapes and city scenes, mainly of Rio de Janeiro.