Quote Originally Posted by Bookkeeper's Son View Post
In some ways, it's like splitting your brain in two, with one half playing guitar and one half singing. McCartney demonstrates this to its max. I think if you know the song well enough, one or the other may be so automatic, that you can even improvise on the other part. And it's also a little like learning to play without looking at your hands, especially your left (if you're a righty) hand - you gotta force yourself to do it until it's second nature.
Yup, I'd agree with that. It definitely helps to have one of the things down cold, which almost always ends up being the guitar part.