Written in Rio in 1946, this work is dedicated to Paulina d'Ambrozio. But Villa-Lobos: Sua Obra (1989) gives the composition date as 1947.
Violin & viola
Villa-Lobos, Heitor. 1947. Duo for violin and viola. New York: Music Press.
The autograph score (16 pp.) is in the Museu Villa-Lobos.
The work had its first performance in New York in Feburary 1948, with Lillian & Joseph Fuchs playing the two parts.
There are eight records in the Villa-Lobos Concerts database as of September 2011.