In "Rabbi Akiba" (1963), for soprano and ensemble, Feldman experiments further with a novel form of notation he used previously in "De Kooning", written earlier the same year. Between conventionally notated bars with time signatures, the score includes extended bars without time signatures, in which sequences of notes joined by broken lines, indicating the sequence of instrumental entries, are given, along with the instruction: "Each instrument enters when the preceding sound begins to fade." Thus, within the overall time structure of the piece, each player has a certain freedom to choose when exactly their instrument enters.

Feldman apparently saw this as exemplifying a famous saying by the great Jewish scholar and sage, Rabbi Akiva (Akiba), which originally concerned the relationship between predetermination by God and the free will of the individual: "Everything is foreseen, yet freedom of choice is granted."

In an interview with Kurt von Meier in 1968, Feldman said:

Rabbi Akiba said, "All is foreseen, yet choice is given." Now after all, let's not make this so mysterious. How many moves is it possible to make? Especially being that I'm like Mondrian. How many moves can I make? [...] For me, the time structure is the "All is foreseen" within Akiba's metaphor. "Choice is granted" is the moves you make.
The performance below took place on 9 April 2017 in the Katzin Concert Hall at the Arizona State University School of Music, Dance and Theatre. The performers were Stacey Mastrian, soprano, and members of the Arizona Contemporary Music Ensemble. The recording is presented here by kind permission.

Listen to:   Rabbi Akiba (1963) [14:43]