Christian Wolff presented John Cage with a copy of the I Ching, which is a text that uses a symbol system to identify order in chance events, which Cage used to compose his solo piano piece, Music of Changes.
The Wolffs published a series of notable English translations of European literature, mostly, as well as an edition of the I Ching that came to greatly impress John Cage after Wolff had given him a copy. A chart system was also used (along with nested proportions) for the large piano work Music of Changes (1951), only here material would be selected from the charts by using the I Ching. In early 1951, Wolff presented Cage with a copy of the I Chinga Chinese classic text which describes a symbol system used to identify order in chance events. 
