The sweet, passionate melody captivated his heart from the first note; it was full of radiance, full of the tender throbbing of inspiration and happiness and beauty, continually growing and melting away; it rumoured of everything on earth that is dear and secret and sacred to mankind; it breathed of immortal sadness and it departed from the earth to die in the heavens.”

from Home of the Gentry by Ivan Turgenev

“A process is said to by aleatoric if its course is determined in general but depends on chance in detail” -Werner Meyer-Eppler

Indeterminacy in composition.
Indeterminacy in performed sequence of events.
Indeterminacy in notation interpretation.

The heaviest weight – What if some day or night a demon were to steal into your loneliest loneliness and say to you: ‘This life as you now live it and have lived it you will have to live once again and innumerable times again; and there will be nothing new in it, but every pain and every joy and every thought and sign and everything unspeakably small or great in your life must return to you, all in the same succession and sequence – even this spider and this moonlight between the trees, and even this moment and I myself. The eternal hourglass of existence is turned over again and again, and you with it, speck of dust!’ Would you not throw yourself down and gnash your teeth and curse the demon who spoke thus? Or have you once experienced a tremendous moment when you would have answered him: ‘You are a god, and never have I heard anything more divine.’ If this thought gained power over you, as you it would transform and possibly crush you; the question in each and every thing, ‘Do you want this again and innumerable times again?’ would lie on your actions as the heaviest weight! Or how well disposed would you have to become to yourself and to life to long for nothing more fervently than for this ultimate eternal confirmation and seal?

Nietzsche, The Gay Science, section 341