I've got a rebuttal, but as I'm late for an appointment, I'll give the Reader's Digest version.

How many of you can do Trigonometry in your head? I've been able to do trig since high school. I once tried to explain to someone how the (cos theta, sin theta) pair was just the rectangular coordinates for a line with the polar coordinate of (1, theta) and to convert to a different measurement all you had to do was multiply each by the line length. It's very simple.

But how many of you reading that just learned how to do Trig? It took me a long time to understand that some people just don't grasp ideas that, to me, are obvious.

I know the tones associated with the lines and spaces - at a glance. Bass, treble, and alto clef (though when the alto clef is shift I have to refer to mnemonics). I know the time values associated with notes. I can listen to two tones and tell you what the interval is. Give me a sheet of music and an organ, tin whistle, or guitar, and I can play it - slowly. But I CAN NOT visualize (audialize?) in my head what it should sound like.