Samuel Rosa de Alvarenga (born July 15, 1966) is the former lead singer, primary composer and guitarist of Brazilian rock band Skank. He has a psychology degree from Universidade Federal de Minas Gerais. Samuel writes the music for most of the group's songs, with 80% of the lyrics by Chico Amaral. Other songwriting partners were Nando Reis, Arnaldo Antunes, and Lô Borges. Samuel is a football fan and supports Cruzeiro.