Have you all seen this about perfect pitch.

[Three Valves]

When people speak of perfect pitch, what pitch system do they refer to? Equal temperament, mean-tone, just, well-tempered, whatever? And how wide are their "slots"?

If it is just 5 cents flat they ear it up!!

[Doug Elliott]

It depends. Piano players develop equal tempered perfect pitch. Or in the case of someone who grew up playing an out of tune piano, that becomes their reference - I knew someone like that.

For others, the slots can be wide. It's entirely possible to follow different temperments. You can learn to hear and recognize whatever you learn to hear and recognize. And I do think it happens very early in life, reinforced continually, and probably can't be learned after a certain point.

I suspect that the 60Hz hum, and continually hearing off-pitch recorded music, are the reasons it tends to decline eventually.

[timothy42b]

I suspect that the 60Hz hum, and continually hearing off-pitch recorded music, are the reasons it tends to decline eventually.

I wonder if that is changing now. With the ubiquitous cheap electronic tuner, groups tend to be a lot closer to A440 than I remember. Playing in tune can still be hard with some players, but not because the whole group is way off. Also popular music is usually autotuned, so it's a lot closer.

[timothy42b]

If we could convince the utility companies to change the US electric power supply from 60 Hz to 58, we'd have a soft Bb reference playing in nearly every room. 60 is halfway between Bb and B and drives me nuts.

You would have just LOVED the first two years of my engineering job when I was project managing the building of electrical substations and spent a lot of time around house-sized transformers that had a very loud 60Hz hum.

I'm still around large transformers that hum. In an electrical room that hum is pervasive, but not so much in a more traditional mechanical room with pumps and supply fans, because those are run with variable frequency drives now.

And then there's the "singing" of high voltage overhead power lines, which electrical engineers claim is corona discharge, but we mechanical engineers know is vortice shedding, akin to how a flute makes sound.