The new prominence of documentary films seems to be an almost universal phenomenon within world cinema. But in each country, the specificity of national-historical experience necessarily imprints its own character on the form. In Brazil, the contemporary documentary movement cannot be understood without reference to the highly political film-making of the early 1960s, a time when direct-sound techniques were becoming a central device in the cinéma vérité of Jean Rouch, or the ‘direct cinema’ of Richard Leacock, Robert Drew and the Maysles Brothers. For Brazilian documentary makers, the synchronized capture of sound and image permitted the presence of popular voices, mainly of peasants and migrant workers, in a cinema deeply concerned with power relations and people’s living conditions.  Already in the mid 50s, the films of Nelson Pereira dos Santos had pointed the way towards following the example of Italian neo-realism and making movies in the streets.
Ismail Xavier on the documentary movement in Brazil, from the January/Febuary, 2012 New Left Review.