Simple to create, but also very effective, were the textures built with many layers of similar berimbau sounds superimposed in a multi-track program.
In the concerto, all these acoustic characteristics of berimbau sounds were explored in many different ways.
There are many times in the concerto when the deformations of berimbau sounds stretch the psychoacoustics of perception beyond the limits of timbre recognition.
This also allowed for a useful link to create a family of synthesised sounds that were related to the berimbau sounds by spectro-morphological similarities.
Berimbau performers vary the pitch by pressing a coin against the string, shortening its length.
Two low pitch "berimbaus" (called "berra-boi" and "mdio") form the base and a high pitch "berimbau" (called "viola") makes variations and improvisations.
Today, many berimbaus are overgrown to 5 feet (150 cm), and tuning options are limited in berimbau ensembles.
The berimbau toques follow the pattern of the supporting instruments, but with a broad arena for improvising.
