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 group's 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 É 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.

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 group's 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 É 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 (Antônio José Waghabi Filho) had a bossa nova group with Miltinho and a flutist, bassist, and drummer, called MPB-5. With Magro (the group's 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.

With all of them as college students, they took a period of vacations in 1965 to go to São Paulo, where they did their professional debut at the Pontifícia Universidade Católica's Theater (Tuca). They met producer Chico de Assis and were invited by him for a season with Quarteto em Cy (which was already professional), on the condition that they abandon other aspirations to devote themselves full-time to their group. Deciding for the music, they opened with Quarteto em Cy at the show No Samba Que Eu Vou, when they met Chico Buarque, also introduced to them by de Assis. From 1969 to 1974, Buarque was almost the fifth member of MPB-4 as all of his shows were with the quartet. Together they toured several countries and were deeply influential on the Brazilian youth. de Assis also introduced them to Manoel Carlos, who was one of the directors of the O Fino da Bossa TV Record show hosted by Elis Regina. MPB-4 participated right on the first show singing together with Regina, which was their definitive consecration.

Back in Rio, they participated in the show Contraponto, together with Quarteto em Cy, Oscar Castro-Neves, and Rosinha de Valença. At the Opinião theater, MPB-4 participated in the historic show O Samba Pede Passagem with Aracy de Almeida, Baden Powell, Ismael Silva, and others. The show was recorded live and released in June 1966 as O Samba Pede Passagem. Also in 1966, they released their first LP, which had the first recording for Buarque's "Olê Olá." Having participated in Nara Leão's show Quem Tem Medo de Nara Leão?, in the same year they defended "Canção de Não Cantar" (Sérgio Bittencourt) at the II Festival de Música Popular Brasileira (Festival of Brazilian Popular Music, FMPB, TV Record of São Paulo), which won fourth place. In the next year's edition of the same festival, the group was consecrated definitively with "Gabriela" (Maranhão) and "Roda Viva" (Buarque), achieving, respectively, sixth and third places. Also in 1967, they participated in the II FIC (International Song Festival, TV Globo, Rio) with "O Sim Pelo Não" (Alcivando Luz/Carlos Coquejo) and "Cantiga" (Nelson Motta/Dori Caymmi), which reached sixth and ninth places. In 1968, they opened a show shared with Buarque at the Teatro Toneleros, and also had a season in São Paulo. Three years later, they did the historic show Construção at the Canecão with Buarque, Jacques Klein, and the Orquestra Sinfônica Brasileira (Brazilian Symphony Orchestra) conducted by Isaac Karabtchevski. In the next year, MPB-4 toured Portugal and in 1973, Buenos Aires, Argentina, both with Buarque. In 1975, they participated, with Buarque, in the show República de Ugunga. In 1980, the group released, together with Quarteto em Cy, the children's LP Flicts/de Ziraldo e Sérgio Ricardo. Recording another children's LP in the next year with "O Pato" (Toquinho/Vinicius de Moraes), they had the song presented in the TV Globo musical A Arca de Noé. The LP Caminhos Livres (1983) had another of their hits with an Aldir Blanc song, "A Nível De..." (with João Bosco). In 1991, the quartet launched another of their themed albums, the CD Sambas da Minha Terra, dedicated to the works of Dorival Caymmi, Toquinho/Vinícius, Zé Kéti, and Ary Barroso, among others. Always doing shows and recording frequently, the group commemorated their 30-year career in 1995 with the show Arte de Cantar and the eponymous album. ~ Alvaro Neder, All Music Guide