So, I've got perfect pitch, and its not quite that black and white. For context, I can do all the regular perfect pitch superpowers (except for door rattles, which don't really rattle with a single tone), and have had it from a young age. When I first remember having it, I could only reliably recognise an A (and would have to count upwards to other notes), but unambiguously meet any definition as an adult
Many things that are considered perfect pitch skills take practice, and the OP is absolutely correct in that certain timbres are easier to classify than others. As a kid I would have had a harder time telling you the pitches if two woodwind instruments were playing a chord, vs two stringed instruments, due to familiarity. Its something you tend to work on accidentally as a background process as a musician
Much of perfect pitch discrimination is an active process though, eg being able to split up a song into its constituent parts and pick out the notes of each line is something you have to learn. All perfect pitch does is give you the ability to perform that discrimination, but anything more than that is a skill. For things that people consider to be perfect pitch skills (tone classification in a cluster), there absolutely are good days and bad days
Lots of pitches in nature aren't especially clean - nor are musical instruments, which is what makes them of varying ease to classify when you're unfamiliar. There are harmonics that can be make it hard to classify, or the central tone can be washed out in noise or similar tones. Its like trying to identify the dominant frequency in white noise, it takes practice
Its likely that OP had perfect pitch as a kid (demonstrating pitch classification), and simply never really capitalised on it mentally to develop it. Because you're right in that no adult has ever experimentally been demonstrated to have learnt this, even with extensive training and musical experience
I agree with all of the above, including the hypothesis that the OP likely had absolute pitch to some degree as a child and not thought about it. Everyone I personally know with perfect pitch (including myself) started engaging with music seriously very early on in life. (I don't know quickly I acquired it because it's always been as easy as identifying colors and I didn't know it was unusual until my piano teacher noticed.)
For me piano is definitely the easiest instrument to identify, I'm sure largely because it's what I've played all my life. Pipe organs are the worst. I assume that in general the purity of the tone correlates negatively with ease of identification.
Many things that are considered perfect pitch skills take practice, and the OP is absolutely correct in that certain timbres are easier to classify than others. As a kid I would have had a harder time telling you the pitches if two woodwind instruments were playing a chord, vs two stringed instruments, due to familiarity. Its something you tend to work on accidentally as a background process as a musician
Much of perfect pitch discrimination is an active process though, eg being able to split up a song into its constituent parts and pick out the notes of each line is something you have to learn. All perfect pitch does is give you the ability to perform that discrimination, but anything more than that is a skill. For things that people consider to be perfect pitch skills (tone classification in a cluster), there absolutely are good days and bad days
Lots of pitches in nature aren't especially clean - nor are musical instruments, which is what makes them of varying ease to classify when you're unfamiliar. There are harmonics that can be make it hard to classify, or the central tone can be washed out in noise or similar tones. Its like trying to identify the dominant frequency in white noise, it takes practice
Its likely that OP had perfect pitch as a kid (demonstrating pitch classification), and simply never really capitalised on it mentally to develop it. Because you're right in that no adult has ever experimentally been demonstrated to have learnt this, even with extensive training and musical experience