According to Tony Morris of GuitarAlive.org, a long-lost recording of Barrios has been found. It’s a recording of Barrios himself playing Bicho Feo.
The original 78 recording by Barrios himself has been found independently by 2 different sources, both within a period of two months. Bicho Feo, or “Ugly Bug” is a humorous tango that Barrios used to play at the end of his concerts to bring the house down. The manuscript of the score has never been found, but Barrios recorded it on the Atlanta label in Argentina, and two copies have been found! Huge news for the classical guitar world.
There are lots of references to Bicho Feo in Six Silver Moonbeams: The Life and Times of Agustin Barrios Mangore