"My teacher Louis Vierne was born blind. He had an operation when he was twenty-six and could see a little. He found one thing unbearable, the way a head is attached to the neck and shoulders. For him, that was horrible. Also, if he was told: 'Pick up this pencil!' he would answer, 'I can't, it's too far away'. But he would want to pick up a house because it was large and he saw it close up. It took him one or two years to understand the relationship of large and small to proximity or distance. He used to see large objects as close and small ones as distant." "But to what degree does any of us see things as they really are? Someone who hears the organ will say, 'Oh!, it must take such strength!' Now, to play an organ with five hundred stops, you exercise the same pressure as when you play a little pipe organ with two pedals. Those who hear the organ for the first time are stunned by its power. One doesn't employ extra force. One obtains the same musical colouring by external means, in much the same way a shadow plays on the colour of an object."
(Nadia Boulanger, interviewed by Bruno Monsaigneon.)