One of the most important Brazilian vocal/instrumental groups of all time, MPB-4 always devoted its activities to MPB (a specific genre of Brazilian popular music employing sophisticated lyrics, melodies, and harmonies) where the commercial aspect was subordinat to the groups artistic standards. They reinvented the Brazilian vocal groups with their jazz free style focused on samba and also launched the careers of several soon-to-be masters of Brazilian music, such as Aldir Blanc (with his Amigo Pra Essas Coisas with Sílvio da Silva Jr.). Having recorded more than 30 albums since 1964, many of them of utmost historical and artistic significance, they had a considerable part of this production released in countries like the U.S., Norway, Canada, Japan, Portugal, Mexico, Argentina, and others. The group was awarded with the Sharp prize as the best MPB group in 1987, 1989, and 1995. In 2001, MPB-4 completed a 36-year career with the same formation (registered in the Brazilian edition of the Guinness Book of Records of 1996).

In 1963, a trio formed by Rui Alexandre Faria (Rui, the lead vocalist), Aquiles Rique Reis (Aquiles), and Milton Lima dos Santos (Miltinho) in Niterói (Rio de Janeiro) started to perform at the Popular Center of Culture (CPC) of the National Student League (UNE). The CPC of Niterói was founded in Aquiles home. At the same time, Magro (Antnio José Waghabi Filho) had a bossa nova group with Miltinho and a flutist, bassist, and drummer, called MPB-5. With Magro (the groups lifelong musical director) invited to join the original vocal trio, the quartet became known as Quarteto do CPC. With the extinction of the CPC (and of the UNE) after the military coup in 1964, the group adopted the name of MPB-4, playing in local bars and doing a double single with the first recording of Zé Kéti/Elton Medeiros Mascarada with Samba Bem (Luís José) and other songs.