> I was born with something not quite like perfect pitch, but when something is even slightly off tune it caused physical discomfort for me.
Define off tune? 12 TET? Just intonation? Bohlen-Pierce (56 TET) ?
The "in tune" notes are as much a function of culture as physics.
> The "in tune" notes are as much a function of culture as physics.
Huh? Pitch ratios are not a social construct, it's just arithmetic.
There's definitely some physical underpinnings--most music systems have the concept of an octave which maps nicely onto frequency-doubling, for example. But there's also culture: For a purely Western example, even-tempering is in tune, but you'll hear different "beat patterns" for a given interval than with an instrument tuned for music in just one key.
And the choice of which ratios "sound good" is cultural, to some extent.