 "Uirapuru" is a name, derived from the Tupi language, applied to various members of the bird family Pipridae found in Brazil.The bird whose song Villa-Lobos used as a compositional theme is "Cyphorhinus arada", the uirapuru-verdadeiro or musician wren, also known as the organ wren or quadrille wren, a bird with an astonishing variety of song patterns.Villa-Lobos likely based his uirapuru theme on a transcription made during an expedition in 1849–50 by the British botanist Richard Spruce, and published in 1908 .