Thanks to the presence of a string quartet within the formation, Piazzolla was able to evolve a more complex contrapuntal language, to which was added the rhythmical improvisations of the piano, guitar and percussion, providing a language close to that of cool jazz and rock, a tendency which would become more accentuated in the later European stage of Piazzolla’s career.
There are also recordings of them accompanying the singers Amelita Baltar and Mina, and of the music from Bernardo Bertolucci’s film Last Tango in Paris.
Some of this music was not used in the film due to its late completion by Piazzolla, who was busy preparing for his first concert at the Teatro Colón in Buenos Aires in 1972.
Piazzolla re-formed the Conjunto 9 in 1983, with some changes in its formation, for his second concert at the Teatro Colón on 11 June where they played together with the Buenos Aires Philharmonic, conducted by Pedro Ignacio Calderón.
This time the Noneto was made up of: Astor Piazzolla (bandoneon), Pablo Ziegler (piano), Fernando Suárez Paz, (violin), Oscar López Ruiz (electric guitar) and Héctor Console (double bass) plus Hugo Baralis (2nd violin), Delmar Quarleri (viola), José Bragato (cello) and Enrique Roizner (percussion).