Author: vboboe
Date: 2007-06-05 07:06
... well maybe not fibonacci but when an opportune guitar book came my way i discovered the 12 fret positions and 12 semitones up each string. That lead to realising that Major and minor thirds are fretted on 3rd and 4th positions, and the Dom Fifth on 7th position
OK said i to myself, reed fibres are strings too, Thirds / thirds and Fifths (and 2-3 octave Crows) are important triad / chord notes, so do these relate to how one cuts a reed? OK, so let's just see this as a math game at the moment, but note the correspondences on the reed in passing
So i crunched the numbers for twelfths of a 23.5 mm piece of cane (being pretty close scale of 1mm to 1inch of oboe). I also crunched the numbers for fractions of half-quarter-eighth and fifth-tenth.
Where any two numbers from these fractional measurements come pretty close in mmm to any 12th fraction, i'm calling that a 'node' because two occurences strengthen that measurement
The 'open string' would be equivalent to the aperture end of the reed, so 'positions' are identified from the tip down to the thread, but actual mm measurements are from butt end of cork as usual. The thread at 47mm represents octave up, 12th position -- hm, we crow the reed at the thread
Here are some of my discoveries
minor third nodes between 64.25 - 64.62
65mm is my teacher's measurement for base of the tip
-- but the only mathematical fraction that produces 65.ought is one-fifth
so maybe 65mm makes the minor third flatter -- darker reed tone???
Major third doesn't have a node, but does have a 12th fraction at 62.3
62mm is my teacher's measurement for the Catch. The Catch is a drastic cut, maybe a way to strengthen an otherwise weak measurement at the Major 3rd position???
Maybe we could get more minor "true oboe'' tone colour if we didn't strengthen the Major and cut the base of the tip at 64.3?
The Heart wood spans minor and Major third semi-tones -- frets 3 & 4 on guitar string
Dominant 5th nodes between 56. 2 - 56.7
My teacher's method doesn't specify measuring anything there, but windows are scraped by starting 'about halfway down the back', so that's would be equivalent to 8th Fret position on the A string = F note
However, if one cut the base of windows (window-sills) at 56.3 for the Dominant 5th instead? ... see note 2 sentences below
Leading Note (7th) nodes between 49.3 - 49.8
There's no fraction at all at 57 or 59mm -- so maybe any uneven thickness at these measurements really ''deaden'' reeds?
Since E is Dom 5th to A, if E's sharp in oboe, take bit more more wood off at equivalent E note at 56.3 mm to adjust reed to oboe ???
And yes, of course reed fibres aren't guitar strings, and yes of course each fibre isn't tuned to the same frequencies ... but they definitely do have frequencies of their own
It's the uncut middle bark layer fibres that run the whole length of reed and do most of the vibrating reponsible for reed sound?
It would seem to me cutting reeds to produce 'chords' is already being done anyway?
Is 1-3-5-8 a fibonacci sequence?
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