I'm currently practicing for a show with my cello tuned down a half-step, and it strongly conflicts with my ear<->muscle memory. Similar experiences when jumping between standard tuning and the Bach 5th Suite (A string tuned down to G) or Kodaly Solo Sonata (lower two strings tuned down a half step).
That doesn't require perfect pitch. Most of the YouTube musicians noted for making videos of going on sites like Omegle and its successors and taking requests which they the then play perfectly after a short listen to the original if they don't know the song do not have perfect pitch for instance. Examples include The Dooo (guitar and piano), Frank Tedesco (piano), and Rob Scallon (violin).
There's also an element of violin-specific pitch detection; if you play violin for long enough, you can recognize the specific timbre of different notes on a violin (particularly easy for open strings) which helps ground you while listening to a tune.
Because most people don't have perfect pitch, (Western) music is built on the relationships between pitches rather than the absolute pitches. So with absolute pitch, you can play something by ear; with relative pitch, you can play something by ear in any key.
Learning to think of the notes you're playing relatively instead of absolutely is already a difficult leap for most musicians, and my understanding (though I don't have absolute pitch so I can't compare from experience) is that absolute pitch makes this skill significantly harder to acquire, since you have to retrain your ear in addition to your hands.
If I were offered a choice to trade my sense of relative pitch for absolute pitch, I most certainly would not take it. I know well the feeling of incongruity when my muscle memory is stuck in the wrong key, and absolute pitch would mean I'm stuck there all the time instead of being just able to shake my head, focus on the new key, and clear my mind of the old.
The tonal speaker hears a much wider and more precise range of tones, but that precision also kind of hinders them in a way because they can't not hear it. On the other hand speak with a tonal native speaker who's also learned a non-tonal language and they can understand your mistakes (in their native tongue) perfectly, because they essentially have already untrained the tonal instinct. But I'm sure hearing those tonal mistakes feels quite jarring to them nonetheless, like when you're listening to a musician who gets a chord wrong - it just hurts.
The native English (many other Indo-European languages also have similar systems) speaker is very unlikely to make a pronunciation mistake in this manner but even very accomplished francophone speakers of English struggle with it even after being corrected.
For example here’s French cabinet minister Bruno Le Maire pronouncing “damages” as “daMAges” https://youtu.be/qKWFsg5uHKo
I learned this is especially valuable when switching between instruments with different constrained ranges (you can just adapt), as well as your voice changing over time.
Like motion sickness with musical tones - you see one thing on the page, you have a sense for what "note" you're playing, but out comes something else.
I have perfect pitch but it's not really useful, except for noticing that my instrument is getting sharper. But that doesn't matter since you have to be in tune with the rest of the band/orchestra.
In reality, you put your fingers in the position for a C on that specific instrument and you get a C. The name "transposing instrument" is misleading; the instrument itself does not transpose. It's purely a notation convention, intended to give you a consistent mapping between notation and fingering so it's easier to switch between instruments. If you only play one instrument there's no need for it. And even if you do, it's not strictly necessary, e.g. recorders are commonly available in both C and F and are conventionally not notated transposed. Professional players routinely switch between them for different pieces.
I expect it would be possible to train an image-processing LLM to OCR sheet music so it can be automatically transposed and re-engraved for compatibility with absolute pitch.
OK, my fault for poor communication. Let me try strongly typing this.
Clarinet: you play a finger-C, out comes a soundwave-Bb. Flute: you play a finger-C, out comes a soundwave-C. And finger-C is polymorphic on the instrument, or something.
Aside from that, I don't disagree with you.
One consideration is that with most instruments, being keyed the way they are, if you immediately transpose via LLM some of those instruments will have almost all their notes in unexpected ledger lines.
Which could have (en)grave implications.
Keyboard instruments in other temperaments (for example some Baroque tunings) may split the black keys (for example) into separate sharp and notes; sharps are used for sharp keys and flats for flat keys.
Choirs and instrumentalists who can dynamically adjust the pitch of individual notes will often do so for better tuning. (Some software instruments can also adjust tuning dynamically as you play.)
Many (if not most) pieces of music (perhaps most famously Bach's Well-Tempered Clavier) were composed with a particular temperament in mind.
A just intoned major third is about 14 cents flatter than a major third played on a 12 tone equal temperament tuned instrument (e.g., piano).
I'm not sure how much this matters in terms of having or not having perfect pitch though. Some people with perfect pitch can hear the difference between JI and 12TET and correctly their singing accordingly.
Someone shared this recently: https://www.youtube.com/watch?v=XwRSS7jeo5s I struggle to conceive being able to hear the difference, but _singing_ it entirely blows my mind
Of course if you sing Indian classical music (or several other non-Western musical traditions) then you will learn to sing quarter tones.