Octeto Buenos Aires was a tango octet formed in 1955 by the Argentine bandoneon player Astor Piazzolla. The ensemble pioneered nuevo tango, a new approach to tango which, until then, had been dominated by the traditional orquesta típicas of the 1930s and 1940s. This would mark a watershed in the history of tango and set Piazzolla on a collision course with the tango establishment.
Piazzolla had served his musical apprenticship as a tango bandonoenist in a number of orquesta típicas, including those of Anibal Troilo and Francisco Fiorentino. In his search for new ways of expressing himself musically Piazzolla formed his own orchestra of this type in 1946. Unsure of which way to turn he disbanded his orchestra in 1950 and began to study classical music which took him to Paris in 1954, where he studied classical composition and counterpoint with Nadia Boulanger. During his time in Paris, he had the opportunity of listening to many jazz groups, including the octet of the saxophonist, Gerry Mulligan. Impressed by the enthusiasm of the musicians and the obvious pleasure they derived from improvising together, something he had not observed in the world of tango, he decided to form Octeto de Buenos Aires on his return to Buenos Aires in 1955.