Background: John Milton Cage Jr. (September 5, 1912 - August 12, 1992) was an American composer and music theorist. A pioneer of indeterminacy in music, electroacoustic music, and non-standard use of musical instruments, Cage was one of the leading figures of the post-war avant-garde. Critics have lauded him as one of the most influential composers of the 20th century. He was also instrumental in the development of modern dance, mostly through his association with choreographer Merce Cunningham, who was also Cage's romantic partner for most of their lives.
Context: In 1987, Cage completed a piece called Two, for flute and piano, dedicated to performers Roberto Fabbriciani and Carlo Neri. The title referred to the number of performers needed; the music consisted of short notated fragments to be played at any tempo within the indicated time constraints. Cage went on to write some forty such pieces, one of the last being Eighty (1992, premiered in Munich on 28 October 2011), usually employing a variant of the same technique; together, these works are known as Number Pieces. The process of composition, in many of the later Number Pieces, was simple selection of pitch range and pitches from that range, using chance procedures; the music has been linked to Cage's anarchic leanings. One11 (i.e. the eleventh piece for a single performer), completed in early 1992, was Cage's first and only foray into film.  Another new direction, also taken in 1987, was opera: Cage produced five operas, all sharing the same title Europera, in 1987-91. Europeras I and II require greater forces than III, IV and V, which are on a chamber scale.  Already in the course of the 1980s, Cage's health worsened progressively: he suffered not only from arthritis, but also from sciatica and arteriosclerosis. He suffered a stroke that left the movement of his left leg restricted, and, in 1985, broke an arm. During this time, Cage pursued a macrobiotic diet. Nevertheless, ever since arthritis started plaguing him, the composer was aware of his age, and, as biographer David Revill observed, "the fire which he began to incorporate in his visual work in 1985 is not only the fire he has set aside for so long--the fire of passion--but also fire as transitoriness and fragility." On August 11, 1992, while preparing evening tea for himself and Cunningham, Cage suffered another stroke. He was taken to St. Vincent's Hospital in Manhattan, where he died on the morning of August 12. He was 79.  According to his wishes, Cage's body was cremated, and the ashes scattered in the Ramapo Mountains, near Stony Point, New York, the same place where Cage scattered the ashes of his parents, years before. The composer's death occurred only weeks before a celebration of his 80th birthday organized in Frankfurt by the composer Walter Zimmermann and the musicologist Stefan Schaedler was due to take place. The event went ahead as planned, including a performance of the Concert for Piano and Orchestra by David Tudor and Ensemble Modern. Merce Cunningham lived another 17 years, dying of natural causes in July 2009.
Question: what kind of musical style was Eighty?

Answer:
Two, for flute and piano,