Mário Lago, excelling in several other fields besides the popular music, wrote classic marchinhas of carnival and other immortal songs like "Oh, Que Saudades da Amélia" and "Atire a Primeira Pedra." Preferring to record less but to preserve quality, his production was kept small but precious. Lago was recorded by artists like Carmen Miranda ("Aurora" became an international hit), Francisco Alves, Carlos Galhardo, Joel e Gaúcho, Ataulfo Alves, Nora Nei, Jorge Goulart, Deo, and many others. Son of conductor Antônio Lago, he published his first poem, "Revelação," at the Fon-Fon magazine in 1926. He studied piano with Lucília Villa-Lobos until the seventh grade. In 1933, he began to write theatrical revues. With Álvaro Pinto, he wrote +Figa de Guiné and +Grande Estréia. The first lyrics were for Custódio Mesquita's song "Menina, Eu Sei de Uma Coisa," recorded by Mário Reis in 1936. In 1937, he wrote (again with music by Custódio) the fox trot "Nada Além," which was immortalized by Orlando Silva, later receiving several re-recordings. Also with Custódio as his partner, he wrote a series of songs for revues enacted in the famous showroom Casa de Caboclo.

As a composer, his first song was "Devolve" (1940), recorded by Carlos Galhardo. He had one of his biggest hits in that year with "Aurora" (with Roberto Roberti), recorded by Joel e Gaúcho. The song was a big success in next year's carnival and became an international hit as Carmen Miranda's interpretation, being included in her regular repertory. In 1942 he wrote another one of his greatest hits, "Ai Que Saudades da Amélia," with Ataulfo Alves. Two years later, he wrote another of his immortal hits, "Atire a Primeira Pedra," with the same partner. In that year, he opened his career as radioman, being hired by Rádio Pan Americana (São Paulo SP), and in 1945, by Nacional (Rio). In 1948, he went for Mayrink Veiga, in 1949 for Bandeirante (São Paulo), and in 1950 for Nacional. In the radio, he performed several different tasks, as producer, writer, host, and actor.

As an actor, he also worked in theatre, opening with +O Sábio in 1942, followed by several other plays. In 1953, he created another success, "É Tão Gostoso, Seu Moço," with Chocolate, recorded by Nora Ney. With the same partner, he would write his last hit in 1962, the samba "Três Sorrisos." In the cinema, he acted in the films #Balança Mas Não Cai (1953), Glauber Rocha's #Terra em Transe (1967), and #São Bernardo (1973). He has also had success in TV, working in several shows in diverse genres, from prime time soap operas and humor to drama, since his opening in 1954 at TV-Rio. Gilberto Gil paid tribute to him with the song "O Mar E O Lago." With several books published, he also had his biography written by Mônica Veloso (-Mário Lago - Boêmia e Política, Editora Fundação Getúlio Vargas, Rio). ~ Alvaro Neder, Rovi