The 2 brothers called themselves "Los Indios Tabajaras" They were native northern Brazilian Indians of the Tabajaras tribe. Their story is probably part fable, but they claimed to have found a discarded guitar in the jungle. They took turns practicing and soon learned local folk songs. They typically dressed in elaborate Indian costume, complete with feathered head pieces. They started touring the world in the 1940's, playing traditional Brazilian music. In the 1950's they took a break from touring and studied classical guitar technique. I'll let you be the judge of the results. This was probably recorded in the mid to late 1950s.