harrisonreed wrote: ↑Thu Oct 24, 2024 10:35 am
Doldom wrote: ↑Thu Oct 24, 2024 9:30 am
To instrument makers, is there a design philosophy that consciously forcing up intonation of 7th partial so it can be used? (with tuning slides pulled in and stick out first positions)
I still think the brass instruments should have 30 cents low 7th partial.
I am not sure what this means exactly, but if you meant to say that Ab is still not possible in 1st with the tuning slide pushed completely in, you're objectively wrong.
I think it's not an oddball partial that should be fixed with design tweaks, but rather it's hidden secret of nature's beauty. It unlocks whole new possibility of septimal intervals, just we don't use that interval in modern music.
If someone has sufficiently long hands and play first position stick out long enough from bumpers and make use of 7th partial Ab and it's in-tune with 12-tet, (and still have viable 7th position E and B), I'm totally fine with it and there is no debate. But, that is possible maybe because, there might some design tweaks exist that is forcing up the 7th partial.
I don't really know what you're talking about with these septimal intervals, that sounds like some deep 7-limit JI concept, but surely that specific interval's JI tuning would be possible using Ab in 3rd, which can be manipulated as far sharp or flat as you could possibly want. Playing it in 1st doesn't give you any "new" tuning option -- the tuning is much less flexible than in the standard 3rd position.
Have you ever wondered why the 7th partial is so low in the first place?
If a trombone is tuned to A=440, then fundamental frequency wound be approximately 58.3 Hz.(this is pedal Bb)
Any partials that is stacked upwards have a frequency that has integer ratio with the fundamental frequency. (Let's assume that a trombone follows "perfect" harmonic series.)
2nd partial = 2*58.3Hz = 116.6Hz (Bb2)
3rd partial = 3*58.3Hz = 174.9Hz (F3)
4th partial = 4*58.3Hz = 233.2Hz (Bb3)
5th partial = 5*58.3Hz = 291.5Hz (D4)
6th partial = 6*58.3Hz = 349.8Hz (F4)
7th partial = 7*58.3Hz = 408.1Hz (Ab4)
8th partial = 8*58.3Hz = 466.4Hz (Bb4)
etc...
But, in equal temperament, F3 is 174.6Hz. D4 is 293.7Hz. F4 is 349.3Hz. Ab4 is 415.4Hz.
There is so much discrepancy at Ab4 note (408Hz vs 415Hz) and it's approximately 31 cents difference.
But, as Aidan said before, there is very few trombones that really have 31cent low 7th partial. (I'm talking about no slide adjustment. If you blow Bb3 in stick-out first position, don't do any slide adjustment and blow Ab at that same position. Let's assume that someone is playing valve trombone or trumpet. It will make this more understandable.) I'll check my trombones again with tuner, But if Aidan is right that many trombones have in fact "not-that-low" 7th partial, there must be some design element that is forcing the intonation of the partial up to that point. So that with the "forced up 7th partial" slide trombone, some can use 12tet Ab in first position, with pushed tuning slides and stick-out first position for other notes. That was the point that I wanted to say.
If a trombone is built with "real 31cent low 7th partial", then, it will be much harder to achieve 12-tet Ab in first position, even if you push the tuning slide all the way in. Even harder, in countries that is using A=442 or 443Hz. That was my point.
And, of course, slide trombone has "The slide" so you can do any interval in any partial whatsoever.
I'm saying that, the "perfect" harmonic series teaches us the hidden interval that we really don't use anymore in modern music.
1st to 2nd partial is an octave. with a frequency ratio of 1:2
2nd to 3rd partial is a perfect fifth. 2:3
3rd to 4th partial is a perfect fourth. 3:4
4th to 5th is a major third. 4:5
5th to 6th is a minor third. 5:6
6th to 7th partial? it's a septimal minor third or subminor third that modern music don't use. 6:7
7th to 8th is septimal major second or supermajor second. 7:8
Assume that someone is playing valve trombone, or trumpet, and, you don't have tuning option for these septimal intervals, except the 7th partial notes, with a very limited note choices.