Choros #05 for piano, subtitled "Alma Brasileira", the "Soul of Brazil". Dedicated to Villa-Lobos' benefactor Arnaldo Guinle.
"The conflict between image and realization unfortunately so common in Villa-Lobos cannot be found here, and that is why it is one of the most important achievements in Latin American piano music despite its small scale." - Eero Tarasti (1995), Heitor Villa-Lobos: The Life and Works, 1887-1959, p. 108.
Thesis: Rust, Roberta. 1991. Piano works from Hietor Villa-Lobos' middle period a study of Choros no. 5, Bachianas Brasileiras no. 4, and Ciclo Brasileiro. Thesis (D.M.A.)--University of Miami, 1991.
Listen to Eduardo Hubert play Choros #05 at the Progetto Martha Argerich site.
Villa-Lobos, Heitor. 1988. Choros no. 5: "Alma brasileira" : for solo piano. Master piano series. Miami Lakes, Fla: Masters Music Publications.
I've only seen one recording of the orchestral version of Choros #05:
This is one of the most-performed pieces by Villa-Lobos - more than 60 records in the database of VL Concerts as of January 2011.