[1] He graduated in Law the Universidade do Brasil, in 1933, getting involved in political activism, and joining the Brazilian Communist Party, PCB.

[1] The first song he wrote was "Menina, eu sei de uma coisa", in partnership with Custódio Mesquita [pt], recorded in 1935 by Mário Reis.

que saudade da Amélia", "Atire a primeira pedra", in partnership with Ataulfo Alves; "É tão gostoso, seu moço", with Chocolate, "Número um", with Benedito Lacerda, the samba "Fracasso" and the carnival song "Aurora", with Roberto Roberti, recorded by Carmen Miranda.

[1] In 1989 Lago joined the Partido dos Trabalhadores, supporting Luiz Inácio Lula da Silva's presidential campaigns in 1989 and 1998.

[15] In 2001, in his honor the TV Globo program Domingão do Faustão created the Troféu Mário Lago, awarded to the best telenovela actor or actress.