“The world, as intended by the Lord of the Realms, is like music. Every voice—that is, every reasoning creature—must sing its assigned part for the song to sound well. That may sound limiting, as though the notes that determine the fate of the world have already been written, but that is not quite the truth.
There is a great deal of room for improvisation, as long as harmony is maintained throughout. Thus, the low voices must not break the flow of the high, so that each moment is a beautiful chord. Do you understand so far?”
(Nicholas Kotar, The Song of the Sirin (Raven Son Book 1), kindle 4016-4019)