A lot changed between Gal Costa's pleasantly straightforward 1967 debut Domingo and her eponymous follow-up two years later. Domingo, also a debut for young Brazilian songwriter Caetano Veloso, featured a set of airy, somewhat standard bossa nova tunes, sung ably by Costa. Mere months after the release of this relatively safe debut, however, Costa and Veloso found themselves alongside Os Mutantes, Tom Zé, and Gilberto Gil, recording contributions to Tropicália: Ou Panis et Circencis, the unofficial manifesto of the Tropicalismo movement. The compilation dove headfirst into avant-garde experimentalism, embracing the psychedelic tendencies happening in American underground circles, and the politically charged energy of radical dissent to Brazil's ongoing military dictatorship. This wild new hybrid of Brazilian pop and far-reaching outside influences resulted in something instantly miles away from everything that came before it, and Costa's self-titled Tropicalismo debut is no exception. The album begins with a flutter of psychedelic echo effects, dissolving into gloriously lush string arrangements and lighthearted organ on "Nao Identificado," a brilliant opening track that introduces Costa's velvety voice, gently at first, as if to ease the listener into the new sounds about to be revealed.