His father, João Joaquim da Costa Braga, was a prosperous merchant, who moved to Brazil in the middle of the 19th century.

The father died in 1897, and the boy entered a boarding school of Colégio Salesiano de Santa Rosa in Niterói, where he remained up to 1904.

His professors were Arthur Napoleão dos Santos, Alberto Nepomuceno, Alfredo Bevilacqua, Agnello França and Antônio Francisco Braga.

The same year Ernani graduated with distinction and a gold medal (the president of the jury was the Polish virtuoso Ignacy Jan Paderewski).

[1] In 1919 Braga entered a competition for a free professorship of piano, and in 1921 he took his teacher Bevilacqua's professor chair at the Instituto Nacional de Música.

[1] He took part in the famous Semana de Arte Moderna in São Paulo (1922) as interpreter of compositions by Heitor Villa-Lobos[4] and Erik Satie's parody on Frédéric Chopin's funeral march (No.2 of Embryons desséchés).

[1] The composer's acquaintance with Villa-Lobos and other modernists along with folklore researches made him a follower of Mário de Andrade's nationalistic ideas.

[4] The most famous work by Braga is Cinco canções nordestinas do folclore brasileiro (Five Songs of Northeastern Brazilian Folklore).

[2] Another important work by Braga is a song collection titled Cancioneiro Gaúcho, composed for the bicentenary of Porto Alegre (1940).