Donga is Ernesto Joaquim Maria dos Santos (1890-1974). He wrote what is often considered the first Samba. That disc dropped 100 years ago, in 1916.
A few years ago I posted this at Tumbling Villa-Lobos. It gives another picture of Villa-Lobos hob-nobbing with the top popular musicians of the day.
"I went out for some bohemian fun with [historian Sergio Buarque de Holanda & journalist Pedro Dantas] the other night. With Villa-Lobos and Gallet, too. We went for an evening of guitar music and a drop of cachaça [cane liquor] with three true Brazilians - Pixinguinha, Patricio, and Donga."
The sociologist & cultural anthropologist Gilberto Freyre meets the greatest popular musicians - sambaistas - of Rio de Janeiro, from a diary entry in 1926. As usual, Villa-Lobos is right in the middle, as is his colleague Luciano Gallet. This is from the fascinating book The Mystery of Samba: Popular Music and National Identity in Brazil, by Hermano Vianna.