I have a limited form of perfect (absolute) pitch, which I am sometimes asked about. Often it’s the same questions, so here they are. No doubt people with better perfect pitch than mine will be annoyed at this impudent upstart claiming the ability, but perfect pitch comes on a spectrum anyway. Apparently some people can identify notes to within the nearest fifth of a semitone, while some can only identify the semitone closest to the note. I am a bit further towards the “tone-deaf” end of that spectrum.
References for notes
Anyway, I have been able to sing a concert A without reference since about the age of 12, I think, on account of having learnt the violin since much younger than then. From then, until about the age of 15, I kind of accumulated more notes I could use as references (A because it’s concert tuning; E because it’s the start of Für Elise; D because it’s the start of Pachelbel’s Canon and of the Libera Me from Fauré’s Requiem). Annoyingly, these were all notes we tune violin strings to; it’s very easy to find the four notes of a violin given an A, because we hear that sound every time we start playing the violin. Eventually I picked up an unreliable B-flat (from a rather rousing Christmas carol), which I always had to cross-check with the A.
Then I started noticing that the F which lies at the bottom of my vocal range had a very distinctive feel on the piano. Not a particular piano - just that I could recognise that F when played on the piano. Similarly, middle C started to feel like a C. I came to be able to reproduce the C vocally, by imagining pressing the middle-C key and singing the note that it played.
That is, I could identify notes ACDEF B-flat. More tentatively, I could identify G as being kind of weedy and characterless (as opposed to the rich understated heroism of F - sounds silly, but I can find no other way to describe it off the top of my head).
I still have trouble with most accidentals (that is, flats and sharps), although I’ve just now realised that I can do F-sharp from Tim Minchin‘s excellent song of the same name and I can do D-sharp from the start of Chopin‘s Nocturne in B. So it’s really just C-sharp, F-sharp, A-flat and B that I don’t have references for. I can identify the white notes (except B, which feels a bit like a chameleon, could be either a C or a B-flat) on a piano by sound, and I can identify all the notes by producing them, or producing the next-door note, and comparing with what I heard.
Having said that, I’m significantly slower and less accurate when there is background noise - particularly tuned background noise. It feels like my internal scale is fuzzy and easily subject to external influence.
Have you always had it? No, I picked it up mid-to-late secondary school. Also, my ability depends on having been playing music recently (by “recently” I mean “in the last week or so”). If the last few weeks have been musicless, I become much slower and less accurate.
What’s it like to have it? No different than otherwise, for the most part. It doesn’t get in the way unless I ask for it, with some exceptions. In particular, I usually listen to a piece of music without noticing the notes, although I am not that fast at identifying most notes, so they might well pass me by before I have a chance to decide what they are. The individual letters of a text don’t bother you.
I said “exceptions”: I am quite sensitive to instruments being out of tune. I don’t know whether I’m much more sensitive than other people in this area - maybe they’re all being polite in pretending not to notice. After a few minutes to get used to the pitch, it usually swamps my absolute representation of notes, and then I stop noticing out-of-tuneness (because I no longer have a reliable baseline).
Can you distinguish sound better than normal? Apparently so, but I don’t think it’s caused by my perfect pitch. On an online test, I scored in the 87th percentile of test takers, reliably distinguishing between 0.75 hertz around 500 hertz. I imagine that’s to do with musical training.