To answer my own question re: perfect pitch, I googled a paper which says: "we also observed a significant association between AP and the age at which an individual first began playing music. For the AP group as a whole, the mean age of starting musical activities was 5.4 ± 2.8 years, whereas, for the non-AP group, the mean age was 7.9 ± 3.2 years (P < .0001)."

Also, it says, perfect pitch is far more common in Oriental people.

[Projoy] But -- as they also point out, I'm glad to see -- the causation could easily run the other way.
[Bm, Raak, Darren, et al] This is a *great* discussion; one from which I am really learning.

I had perfect pitch as a child, but not being a musician, I've never used it, and the skill seems to have decayed. I just tried whistling a middle C, and it turned out to be a tone flat. But maybe I'm channelling Baroque pitch, concert pitch having been invented to boost the E-string industry.

[widey] But we've been here all the time :o) Good to see you back!