The choro group Conjunto Atlântico, one of the most important ever formed in the city of São Paulo, was born in the '50s out of informal rodas de choro (choro get-togethers) realized at guitarist Antônio D'Auria's home. As most of the musicians were industrial workers and not professionals, the initial lineups were varied, revolving around D'Áurea, João da Mata (guitar), Jaime Soares (cavaquinho), Amador Pinto (mandolin), and Osvaldo Bitelli (pandeiro), while later including brothers Isaías Bueno de Almeida and Israel Bueno de Almeida. Although remaining amateur for all its existence, the group received an award in 1974 from the Association of Art Critics of São Paulo.
In 1952, D'Áurea switched to the seven-string guitar. Three years later mandolinist Isaías Bueno de Almeida became a new member of the group, while the rodas de choro at D'Áurea's home in the Barra Funda borough of São Paulo were attracting professional chorões like Altamiro Carrilho, Canhoto, and Jacob do Bandolim. In 1957 the group participated in a radio special dedicated to choro at Rádio Record (São Paulo). Later, mandolinists Walter Veloso and Augusto García and guitarist/vocalist Renato Petra joined the Atlântico. Even as an amateur group, they recorded the LP Conjunto Atlântico in 1958. In the '70s, already established as one of the most important choro ensembles in São Paulo, they were featured in a number of specials broadcast by the TV Cultura network, like As Muitas Histórias da Música Popular Brasileira, MPB Especial, and Primeiro Plano, and also appeared on the TV Bandeirantes network program Depoimento. In 1973 the group had its own weekly show on TV Cultura, Choro das Sextas-Feiras, and subsequently appeared on a series of shows in both São Paulo and Rio.