This is a quote from paddler in the McKenna thread, but I figured this question would be much too thread-drifty to ask there.paddler wrote: ↑Thu Sep 01, 2022 1:58 pm The differences in pitch and tuning between British and American flutes also has an interesting background based in the way concert pitch evolved in the separate locations. It is
almost by chance that we enjoy American flutes with decent A=440 hz tuning. Apparently, while Britain was racing upwards through pitch standards peaking at British High Pitch,
Americans (being anti-British at the time) opted for the French diapason normal standard (A=435 hz). However, that French standard was initially specified at a temperature of 59 degrees F.
American flute makers found that, at more normal temperatures, their flutes played at a higher pitch. In fact A = 435 at 59 degrees ends up being very close to A=440 at 70 degrees.
Lucky us!
I know the general basics of temperature and pitch for whistles and flutes, the idea that warmer=higher, colder=lower. However, it never really occurred to me until a recent very hot streak in my area this summer that I don't exactly know what temperature we're talking about exactly. Our body temperature is supposedly roughly 98.6 degrees F (37C). Presumably the air coming out of us is at a similar temperature. The instrument we're holding is going to be at roughly the ambient temperature of the room it's sitting in, provided it's been sitting there for a long enough time. As we play it, blowing hot air into the flute, it will warm up.
So, the question is, what temperature are we measuring exactly? The temperature of the air itself inside the flute, which is north of 90 degrees F? The ambient temperature of the room? The temperature of the body of the flute, which will stabilize at a sort of middle point between the two? My guess is the last one, since instruments will usually raise in pitch as they get warmer, despite neither the ambient temperature nor the temperature of my body changing much. But I don't quite know the physics behind it, so maybe someone can enlighten me. If I play in a cooler, even for enough time that my flute is as "warmed up" as it can be, will the pitch be inevitably flatter than if I was playing in a sauna? And can one of you science-minded flutemakers create a tuning slide that expands and contracts based on temperature so that my flute is always spot-on no matter how cold or warm it is? I expect royalties if you use that idea...