But there's no such thing as a definitve note frequency, it's arbitrary. If someone with perfect pitch from the 14th century (for example, or even 18th) played what he thought was an A, it would be closer to an Ab or G, so would that mean that he didn't have perfect pitch? If someone says "sing an a", what note do you sing?
Does this mean that if someone with "perfect pitch" went to a very contemporary classical concert, he/she would think that all of the orchestra were sharp (as they often tune to A 445 now)?
I'm not saying perfect pitch doesn't exist, but in a much less mystical way than it seems to be discussed here. I have yet to be given any proof by anyone I have actually had the oppurtunity to talk to that perfect pitch is anything much different from an extension of relative pitch and good memory. Steve Vai alledgedly used to play a tape that simply played an A 440 note in his sleep for so long that now, although he doesn't have perfect pitch, can always sing an A 440, and therefore can pick every note off that. That's not particularly important, but sort of funny.