Question: What saxophonist did bandeoneon player and "nuevo tango" pioneer Astor Piazzolla collaborate with on his album Summit?

Context paragraphs:
Gerardo Gandini: Gerardo Gandini (Buenos Aires, Argentina, October 16, 1936 - Buenos Aires, March 22, 2013) was a pianist, composer, and music director, who became one of the most relevant figures of contemporary Argentine music of the second half of the 20th century.  He studied composition with Goffredo Petrassi and Alberto Ginastera, and piano with Roberto Caamaño, Pía Sebastiani, and Ivonne Loriod.  It is noteworthy that he was Astor Piazzolla's pianist in the Sexteto Nuevo Tango formed in 1989.

La Camorra: La Camorra is the name of a three-movement suite for tango ensemble composed by Ástor Piazzolla.  It was inspired by the Neapolitan criminal organization Camorra and represents Piazzolla's most ambitious compositional statement in length and large-scale musical form, though not in harmony or timbre.  The composer referred to the recording made with his Quinteto Nuevo Tango (in English: New Tango Quintet, often loosely referred to as his second quintet) in 1988 in New York City as "the greatest thing I did", though it was not clear whether he meant as a composition or as a performance/recording.  The lineup for this recording was Ástor Piazzolla (bandoneon), Pablo Ziegler (piano), Fernando Suarez Paz (violin), Hector Console (double bass) and Horacio Malvicino, Sr. (guitar).  This would prove to be the Quintet's last recording and Piazzolla would put together his final ensemble, the Sexteto Nuevo Tango (New Tango Sextet), that same year.

Piazzolla's Orquesta Típica: Piazzolla’s Orquesta Típica (aka the 1946 Orchestra) was a tango orchestra formed in 1946 in Buenos Aires by the Argentine bandoneon player Astor Piazzolla.  This was Piazzolla’s first orchestra of his own and from this spring board he would later go on to pioneer "nuevo tango", a new approach to the genre, with his Octeto Buenos Aires.

Fugata Quintet: Fugata Quintet is a London based chamber group formed in early 2007 at the Royal Academy of Music, where all quintet members were studying at the time.  Fugata principally perform Nuevo Tango music by the Argentine composer Ástor Piazzolla.  The quintet is one of the few independent groups to have produced and performed a fully staged production of Maria de Buenos Aires, the Tango Operita by Ástor Piazzolla and Horacio Ferrer.  The group's name is an homage to Piazzolla's composition "Fugata" from the Nuevo Tango Suite "Tangata Silfo y Ondina".  The current quintet members are: Živorad Nikolić (accordion), Anastasios Mavroudis (violin), Antonis Hatzinikolaou (electric guitar), Anahit Chaushyan (piano), James Opstad (double bass).

Tango: Zero Hour: Tango: Zero Hour ("Nuevo Tango: Hora Zero" in Spanish) is an album by Ástor Piazzolla and his Quinteto Nuevo Tango (in English: New Tango Quintet, often loosely referred to as his second quintet).  It was released in September 1986 on American Clavé, and re-released on Pangaea Records in 1988.

Hommage à Piazzolla: Hommage à Piazzolla is a set of recordings by the violinist Gidon Kremer dedicated to the music of Astor Piazzolla.  Most of the recordings are of a small group with violin, bandoneon (Per Arne Glorvigen), guitar, bass and piano.  These recordings were released on the Nonesuch Records label, initially as a single CD in 1997 (79407 Gidon Kremer: "Hommage à Piazzolla") then in 2012 as part of an 8-cd collection of all Gidon Kremer's previous Piazzolla recordings for the label (515783 Gidon Kremer & Astor Piazzolla: "Hommage à Piazzolla: The Complete Astor Piazzolla Recordings" (8-CD Set)).

José Bragato: José Bragato (12 October 1915 – 18 July 2017) was an Italian-born Argentine cellist, composer, conductor, arranger and musical archivist who, in his early career, was principal cellist in the Colón Theatre orchestra in Buenos Aires, Argentina.  Apart from his involvement in classical music he also performed for many years in a number of Ástor Piazzolla's "Nuevo tango" (New tango) ensembles where his cello solos, which had never before featured in tango, put him in the vanguard of "Nuevo tango" from its birth in the 1950s.  Since then he has done numerous and varied arrangements of Piazzolla's compositions.

Octeto Buenos Aires: 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.

Astor Piazzolla: Astor Pantaleón Piazzolla (] , ] ; March 11, 1921July 4, 1992) was an Argentine tango composer, bandoneon player, and arranger.  His oeuvre revolutionized the traditional tango into a new style termed "nuevo tango", incorporating elements from jazz and classical music.  A virtuoso bandoneonist, he regularly performed his own compositions with a variety of ensembles.

Summit (album): Summit is an album by Argentinean bandoneonist Astor Piazzolla and jazz saxophonist Gerry Mulligan.  The original LP was recorded and released in Italy in 1974.

Supporting paragraphs: Summit (album) Astor Piazzolla
Answer: Gerry Mulligan