I've been picking alot of songs out by ear on my piano. I'm thinking the next stage is to pick/play without looking at the keyboard - that way the eyes are not involved at all. Maybe even wear a blindfold or something.
I think when the eyes are involved then the eyes are trying to look for patterns in the keyboard, or in the scale, like which white/black notes are being played. So even if you're playing by ear to figure out a song, a lot of the actual memorization of a song happens by sight. Because you remember what the patterns look like on the keys as opposed to making a connection between a musical interval and a muscle (ie how much you need to move your hand to get to the sound of an interval).
So wouldn't it be ideal to know how to play by ear by muscle memory only? That way the only thing involved is your ear and muscle memory. Kind of like whistling. I was wondering if other people have tried this and what their experience is.
p.s I'm a programmer by trade, and touch-typing is one of the most important things I know-- been doing it since I was a kid. So shouldn't "touch typing" apply to music as well (?)