João Pernambuco (João Teixeira Guimarães) was an important figure in the development of music for guitar in Brazil. He was involved, along with Donga and Pixinguinha, in the creation of the first important groups of Choroes. [picture from João Pernambuco website]
Pernambuco and Villa-Lobos were close friends, and Pernambuco was a major influence on Villa's first works for guitar, especially the Suite Populaire Bresilienne. The best recent source for information about Pernambuco is Larry Crooks' book Focus: Music of Northeast Brazil. See this post in Tumbling Villa-Lobos.
Pernambuco was involved in an important premiere of a Villa-Lobos work, the Distribuicao de Flores (Distribution of Flowers):
"The guitarist chosen to play for the work's first performance was the most famous and popular choro guitarist of the time, João Teixeira Guimarães, better known as João Pernambuco." [Choro: a social history, by Tamara Elena Livingston-Isenhour, Thomas George Caracas Garcia, p. 189]