But this piece by Patrick Nickelson is well worth a read:
"When Dennis Johnson and I were staying at Richard Maxfield’s apartment in New York, we discussed the amount of choice that a composer retained in a composition that used chance or indeterminacy. We generally agreed that the composer was always left with some choices of one sort or another. At the very least, he had to decide what chances he would take or what he would leave to indeterminacy in his composition. [Later] at my apartment in Berkeley Dennis mentioned that he had been thinking of what we had discussed in New York and that he had discovered a piece which was entirely indeterminacy [sic] and left the composer out of it. I asked, “What is it?” He tore off a piece of paper and wrote something on it. Then he handed it to me. It said, “LISTEN.”"