That's why I wonder what this PP is all about, moonchild. Singing an Ab in Bbm involves more than PP. It also requires a grounding in theory, and there are people who can do that without realising that they are doing it, if you know what I mean. So I don't necessarily think that PP is acquired, either. I think it is a bit like a 6th sense; you either have it or not.

999 times out of 1000 I can tune the guitars to themselves; some of them can be tuned to different scales and different keys, and hold a conversation about nuclear physics at the same time, and I don't think I use one as a reference point to tune the other and so forth. As far as 'remembering the note' is concerned, we probably do do that. But remembering a frequency is a lot different from remembering what happened on holidays last year

I don't know, it puzzles me, or rather the definitions do.
Many theories abound, and one gets trashed when some newer, more 'exiting' hypothesis turns up. I go with the 6th sense one (it works every time *BG*)

B.