Presented in this performing edition as a facsimile of the composer's manuscript, Christian Wolff's Exercise 39 comprises five sections of musical material, each notated with varying degrees of specificity. The score includes fully notated staves of music, a passage of notated rhythms alone, a passage specifying only dynamics, and a passage of still more abstract instructions, all intended to be performed in almost any permutation or combination by two or more players using any sound sources. Only the concluding section features a tempo marking.

Performers must choose which passages to perform and respond to each other's interpretations, as explained in Wolff's detailed performance instructions. Exercise 39 was completed by the composer in February of 2020.