See with your ears, hear with your eyes

When I was in college, one of my music teachers was Mr. Walter Minnear. He had lots of little sayings to emphasize his points, and one of them was that to be a musician you had to be able to "see with your ears and hear with your eyes." By this he meant that you had to be able to see the music on the page and know what it would sound like, and hear the music and know what it would look like on the page. And he was right.