There are two versions of this work, written in 1945: one for strings, and another for mixed chorus.
Thesis: Gerling, Fredi Vieira, and Heitor Villa-Lobos. 2000. Performance anaylsis and analysis for performance: a study of Villa-Lobos's Bachianas brasileiras no. 9. Thesis (D.M.A.)--University of Iowa, 2000.
Thesis: Otero, Stephanie. 1999. Heitor Villa-Lobos' contribution to the national music of Brazil with analyses of Bachianas Braseilieras no. 1 and no. 9. Thesis (M.M.)--New Mexico State University, 1999.
The choral version is dedicated to Aaron Copland.
Choral version: SMATBB
String orchestra version: violins, viola, cello, bass
This comprehensive listing of Bachianas Brasileiras scores from the Major Orchestra Librarians' Association website contains lots of useful information.
This is one of the first scores to be published in the Villa-Lobos Digital project of the Academia Brasileira da Música.
Choral Version:
DVD:
Premiere (orchestral version): 17/11/48, Rio de Janeiro - Theatro Municipal. Quinteto de Cordas da Orquestra Sinfônica Brasileira; Eleazar de Carvalho, conductor
Premiere (choral version): 25/10/75, Rio de Janeiro - Sala Cecília Meireles. Coral Artis Canticum; Nelson de Macedo, director
Most of the performances in the Villa-Lobos Concerts database (77 as of August 2009) are for the string orchestra version, though the choral version is becoming more popular.