Evolution in the mind...

"First bits and crumbs of the piece come and gradually join together in my mind; then the soul getting warmed to the work, the thing grows more and more, and I spread it out broader and clearer, and at last it gets almost finished in my head, even when it is a long piece, so that I can see the whole of it at a single glance in my mind, as if it were a beautiful painting or a handsome human being; in which way I do not hear it in my imagination at all as a succession -- the way it must come later -- but all at once as it were. It is a rare feast. All the inventing and making goes on in me as in a beautiful strong dream. But the best of all is the hearing of it all at once."

Wolfgang Amadeus Mozart