Andrew E,

Actually I have tried it - I taught myself to memorise the pitch of a G by recalling the sound of that string on a bass guitar ... something which for some reason came quite easily.

I was then able to develop this, but after a while I grew bored of it as it served no purpose other than to impress friends and fellow musicians.

Its been years now since I did it, but I reckon I could do it again, but then again, I don't feel any need or desire to.

Being able to tune in to what other people are playing, or just being able to tune a guitar off one of the strings without caring if it is exactly in tune are much more important skills.

The point is to be able to make music and, even better, to be able to make music collectively.

Its an interesting experiment, like doing LSD, but in the long run it doesn't really open any hidden doors and too much of it could be detrimental to your health.