Schedule C
https://www.musicalartists.org/contracts-and-agreements/schedule-c/maria-de-buenos-aires/

Maria de Buenos Aires

Composer:
Astor Piazzolla
Original Language:
Spanish
Librettist:
Horacio Ferrer
Description:
Tango Opera in Two Parts
Time:
20th Century
Place:
Buenos Aires, Argentina
Role Voice Part Classification
El Duende Speaker L
Maria / Shadow Maria Female Singer L
Payador / Porteño / Ladron antiguo mayor / Analista primero / Voz de Ese Domingo Male Singer L
Ensemble 3 Females B
3 Males B
Because this music was originally composed with Tango Singers in mind, it is not possible to assign exact vocal ranges to any of the singers. To fit the voices, sometimes the music will be transposed, or the singer will sing up or down the octave to be in the best part of the performer’s range.
 
Minimum Chorus:  the Ensemble is the Chorus
Chorus Notes:  

The Ensemble must have a minimum of three female and three male singers. They form the following groups:
Voces de los hombres que volvieron del misterio (men)
Voces de las madamas (women)
Voces de los ladrones antiguos (men)
Coro de los analistas (all)
Voces de las 3 marionetas borrachas de cosas (women)
Voces de las amasadoras de tallarines (women)
Voces de los tres albañiles magos (men)