Physics of Music
J.B. Wood
acoustics. While Googling the other day I stumbled on a link for a pdf
download of Alexander Wood's seminal work "The Physics of Music":
http://www.archive.org/details/physicsofmusic006900mbp
The download was free (but I work at a U.S. DoD lab so I don't know what
the experience of others will be). Sincerely,
LJS
I downloaded it free with no problem as PDF. I really like the book
view with the page turns, but I will save the pdf for reference as I
know then that I will have it.
Is Alexander a relative of yours?
Was there anything special you though was noteworthy or is it just a
gift?
Thanks,
LJS
Jack Campin - bogus address
> download of Alexander Wood's seminal work "The Physics of Music":
>
> http://www.archive.org/details/physicsofmusic006900mbp
Great, but it won't *smell* like the original. (High quality science
books of 50-100 years ago are really nice objects to handle).
-----------------------------------------------------------------------------
e m a i l : j a c k @ c a m p i n . m e . u k
Jack Campin, 11 Third Street, Newtongrange, Midlothian EH22 4PU, Scotland
mobile 07800 739 557 <http://www.campin.me.uk> Twitter: JackCampin
J.B. Wood
Hello, LJ, and all. I can't single out any special section(s) of the
book (I did enjoy the discussion on bells, p. 150 ff, however). We have
a hard cover copy in our NRL library and I always felt it covered the
subject material very well. In the section (p. 195 ff) discussing the
"harmonodeik" I constructed one and it's useful for showing where just
intervals fall in terms of a 53-equal division of the octave. AFAIK
Alexander is not in my family tree. Sincerely,
--
John Wood (Code 5550) e-mail: wo...@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337
Orangeboxman
I never knew why, since he is a biology teacher, and not especially
musical.
The Juan G. Roederer book was easier for me, so I knew I was a
musician, not a physicist.
LJS
Hi,
On Page 196 (pdf p.224) There is a diagram II.I. Harmonodeik. It is
showing, I am not sure exactly what. I will try to find time to see
exactly what they are talking about maybe in the Thanksgiving
Holidays, but the illustration is almost an exact replica of what I
pictured when I mentioned the Pie Chart as a basis for your pitch
wheel.
Just though you might want to take a peek if you did not flip through
it that far as of yet.
LJS
LJS
>
> Naval Research Laboratory
> 4555 Overlook Avenue, SW
> Washington, DC 20375-5337
lol, I should have read this a few moments ago. I just posted to Jack
the "harmonodeik" as it reminded me of his project to superimpose
various pitches on overlays. This seemed like it was what he was
describing. I will look at the bells.
At some point, I should relate a story concerning another book on the
acoustics of music that was written one of my old professors. I can't
remember the name at present, but it was reputed to be well respected.
All I have time to say right now is that as a researcher, he was the
best man I ever met when it came to choosing the best faculty members.
He assembled an unbelievable team of people for a small state
university. At some point, maybe I can tell you about the "effect of
pitch from when it originates in a warm environment but is heard in a
cold environment" His conclusions are correct, but I will relate the
story if the opportunity ever comes up. lol (something about snow and
radiators)
I have always enjoyed reading the older science books as it reminds me
of this really interesting "absent minded professor". With that
background, I wonder what kind of staff he had and how long it took
him to produce this work. There is a lot of research and I think a lot
of it seems to be things that were not things that he could have found
on the internet, lol and some of this stuff must be his own work on
some principles and then to select, edit and arrange something like
this with the older technology just staggers one to think of it.
It is somewhat like the Grout Music History Book. Try to find a
filler sentence. Its just facts after facts after facts. With an
occasional conclusion thrown in to keep your interest.
I am really glad to have this in my new cyber library concept. After
loosing things in Katrina, I just don't think I can go through the
emotional trauma of loosing things like that again.
Thanks for the edition.
LJS
Bohgosity BumaskiL
with the sine waves stretching to half the diameter, then piped water
through
the tube. Laminar flow? Full of bubbles? Probably full of bubbles.
Either that or hotter.
"J.B. Wood" <john...@nrl.navy.mil> wrote in message
news:he3d6i$hj6$1...@ra.nrl.navy.mil...
Hans Aberg
> I was just considering what might happen if I mapped my work onto a tube,
> with the sine waves stretching to half the diameter, then piped water
> through
> the tube. Laminar flow? Full of bubbles? Probably full of bubbles.
> Either that or hotter.
You might check out the Ruben's tube (also search YouTube);
http://en.wikipedia.org/wiki/Ruben%27s_Tube
Hans
Bohgosity BumaskiL
news:he64o5$kmj$1...@news.eternal-september.org...
I used to be able to get from wikipedia to a simulation of a guitar string
that slowly illustrated the first five members of the harmonic series, with
buttons to select any combination of the five. Same idea: standing waves.
JavaScript on wikipedia is a political headache, so it was off site.
What I am considering would be different. It would be a tube with sinusoidal
waves within its shape -- a different calibre of tuned muffler, perhaps. If
I were to put it on an enjin, I think the first wave in the pipe should have
the same volume as one of the enjin cylinders. If I speed up my tune so that
the lowest note (or shortest relative beat, whichever results in fewer
oscillations) only gets one oscillation, and plot it on a one-bit GIF, then
I will show you what I mean.
The other thing I might want to do with such a complicated tube is close one
end and blow across the other, then listen to what comes out. I might get a
monotone, like when you do that with a bottle. I might get a chord composed
of all notes in the tune.
http://en.wikipedia.org/wiki/Standing_wave#Physical_waves
That is as close as I can get on wikipedia to the guitar string simulator,
now. It's an English description, and reasonably complete. To the
uninitiated, it's all jargon, though.
This is not it, and it probably does something similar:
http://www.edumedia-sciences.com/en/a541-vibrating-string-guitar
I say probably, because I am just not into making subscriptions, ATM.
Hans Aberg
>>> I was just considering what might happen if I mapped my work onto a tube,
>>> with the sine waves stretching to half the diameter, then piped water
>>> through
>>> the tube. Laminar flow? Full of bubbles? Probably full of bubbles.
>>> Either that or hotter.
>> You might check out the Ruben's tube (also search YouTube);
>> http://en.wikipedia.org/wiki/Ruben%27s_Tube
>
> I used to be able to get from wikipedia to a simulation of a guitar string
> that slowly illustrated the first five members of the harmonic series, with
> buttons to select any combination of the five. Same idea: standing waves.
> JavaScript on wikipedia is a political headache, so it was off site.
>
> What I am considering would be different. It would be a tube with sinusoidal
> waves within its shape -- a different calibre of tuned muffler, perhaps. If
> I were to put it on an enjin, I think the first wave in the pipe should have
> the same volume as one of the enjin cylinders. If I speed up my tune so that
> the lowest note (or shortest relative beat, whichever results in fewer
> oscillations) only gets one oscillation, and plot it on a one-bit GIF, then
> I will show you what I mean.
>
> The other thing I might want to do with such a complicated tube is close one
> end and blow across the other, then listen to what comes out. I might get a
> monotone, like when you do that with a bottle. I might get a chord composed
> of all notes in the tune.
I'm not sure exactly what you want to do, but both suggestions for doing
experiments, and simulations, might be gotten from the Usenet newsgroups
sci.physics (a bit noisy) and sci.physics.research (harder to get posted).
Hans
Bohgosity BumaskiL
To start with, plot a sine wave, then make a surface of rotation out of it.
There is a device that uses light and UV-hardened plastic (dental bondo) to
make such creations into reality. I am not sure of all the things I could do
with such a tube. The first thing would be to plug one end and blow across
the other to see if it makes more than one frequency of standing wave.
_______
http://ecn.ab.ca/~brewhaha/
Hans Aberg
>>> The other thing I might want to do with such a complicated tube is close
>>> one end and blow across the other, then listen to what comes out. I might
>>> get a monotone, like when you do that with a bottle. I might get a chord
>>> composed of all notes in the tune.
>>
>> I'm not sure exactly what you want to do, but both suggestions for doing
>> experiments, and simulations, might be gotten from the Usenet newsgroups
>> sci.physics (a bit noisy) and sci.physics.research (harder to get posted).
>
> To start with, plot a sine wave, then make a surface of rotation out of it.
> There is a device that uses light and UV-hardened plastic (dental bondo) to
> make such creations into reality. I am not sure of all the things I could do
> with such a tube. The first thing would be to plug one end and blow across
> the other to see if it makes more than one frequency of standing wave.
The shape of the body typically affects the overtone spectrum. For
example, clarinets and saxophones use the same single-reed mechanism for
producing the sound, but the saxophone behaves like an open pipe (both
ends open), having all overtones, whereas the clarinet behaves as a
closed pipe (one end open, the other closed) having essentially only odd
partials. The bell of the clarinet causes inharmonicity beyond the
sevenths partial in the low register, and in the high register by the
open holes.
Hans
LJS
Isn't this also somehow related to the Sax being Conical and the
Clarinet being a straight tube?
I know that their OTs are different. This is evident from the Octave
key vs the Register key of the clarinet. Not so clear, however, is the
flute and the Sax having the same fingerings for their octaves as the
flute but the clarinet, having essentially the same shape as the
clarinet having the same fingerings produce the tone a 12th up rather
than an 8th.
I always considered that somehow the Clarinet's "fundamental" started
at the 2nd element rather than the first, but I have not seen any
really good explanation of how and if this is the case.
Can you help clear this up for me?
LJS
Hans Aberg
cylindrical-bore, both single-reed. Sorry for the confusion.
Hans
LJS wrote:
>> The shape of the body typically affects the overtone spectrum. For
>> example, clarinets and saxophones use the same single-reed mechanism for
>> producing the sound, but the saxophone behaves like an open pipe (both
>> ends open), having all overtones, whereas the clarinet behaves as a
>> closed pipe (one end open, the other closed) having essentially only odd
>> partials. The bell of the clarinet causes inharmonicity beyond the
>> sevenths partial in the low register, and in the high register by the
>> open holes.
> Isn't this also somehow related to the Sax being Conical and the
LJS
No problem. So the Sax starts from element 1 of the OTS (because of
the Conical Bore) and the Octave key then gives you element #2 an
octave up but the Clarinet also starts at the Element 1 (OTS) but
since it skips to the next odd because of the cylindrical bore and the
register key gives you the interval of the 12th as this is the next
odd element, the 3rd element of the series?
Am I correct in assuming this?
LJS
Hans Aberg
the octave, the 2nd partial, as the sax and the flute does.
Hans
LJS wrote:
> On Jan 10, 11:31 am, Hans Aberg <haberg_20080...@math.su.se> wrote:
>> Yes, it is the bore, not the bell. Saxes conical-bore, clarinets
>> cylindrical-bore, both single-reed. Sorry for the confusion.
> No problem. So the Sax starts from element 1 of the OTS (because of
LJS
Now we have arrived at my real question. This is the one where I think
that I know the answer but have not been able to find any
documentation to back it up.
The clarinet plays a 12th on the tube before it reaches its next note
at the over blowing (or with the register key) break of the
instrument. This occurs on the instrument between its Bb and its Bnat
note. (The clarinet is pitched in Bb so this is Ab and Anat concert)
So if you were to analyze these two tones, the concert Ab and Anat on
the Bb clarinet, what would the partials be like on each tone. i.e.
Since the Bb(Ab concert) is on the FUNDAMENTAL tone of the clarinet
(it would be the Fundamental of the length of the clarinet or pipe
from the mouthpiece to the open Bb hole) it should have all of the
overtone partials included in this note. This should also be the case
for all the tones down to the written Enat an octave and a half below
this tone. These tones should all have Fundamental, second element,
3rd element etc as it is a single tone produced by a vibrating column
of air. Just as any other vibrating column of air. Maybe because of
the closed end cylindrical aspects it might have only the odd
elements. 1, 3, 5, 7 etc.
BUT on the next register of the clarinet, would its Bnat note have the
same 1, 3, 5 etc, as the low register, or would it have only the 3, 5,
7, 9 elements in the series? In other words, since you are playing in
the second register of the clarinet, is there a fundamental or not to
the tone played?
The same question can be asked of the brass instruments.
On the trumpet, for example, the fundamental is available on the horn,
but is not played as because of the bends of the instrument, it is
almost impossible to play and even when played, it has no real tone.
So I am assuming that when we play the low C and the chromatic tones
down to the low F# using the available tube lengths with the valves,
you would be playing tones with either Element 1 (fundamental) 2, 3,
4, 5 etc, or maybe elements 2,3,4,5 etc and when you move to the notes
available above this, G on the open horn and the chromatic substitute
fingerings down to Db, do these tones (played on the element 3 open
note of the horn) not have either the Fundamental or the 2nd element?
from this open G tone, does the tone start on the 3rd element? Does it
not have the fundamental or first element? or does it somehow have a
vibration on the G, octave G, D, G, B D etc.
I hope that I have been clear with the question. I am basing my
assumption on the apparent truism that on a guitar string, if you put
a strobe on the string, once you play the 3rd harmonic of a string,
you do NOT have the vibration of the notes below it in the OTS but you
only have the ones above it. It seems as though this should carry
through to the wind instruments but I have never seen any
documentation to show that this is indeed the case.
Do you understand what I am asking and do you know anything about this
one way or the other?
Thanks,
LJS
Hans Aberg
You have a site here with a lot of acoustics information:
http://www.phys.unsw.edu.au/jw/clarinetacoustics.html#spectrum
http://www.phys.unsw.edu.au/jw/basics.html
As you can see, that the real behavior of the clarinet is quite
different from the simplified model of only having odd partials.
But suppose you have a pipe which only produces odd partials f, 3f, 5f,
..., over a fundamental frequency f, and overblows so that the 3f is
the fundamental. Then as it is the same pipe, the overtones must be from
the original series of odd numbers times f, but it must also swing
together with the oscillator that generates them, which are 3f, 6f, 9f,
12f, 15f, ..., but 6f and 12f are not possible since not in the original
series, so this is 3f, 9f, 15f, ... If you put g = 3f, this is g, 3g,
5f, ... In other words, it has the same type of spectrum.
Roughly what is going on here is that the tone will behave as a set of
independent oscillators. If there is a way to feed them, they will
swing. If they are sufficiently strongly coupled, like when continuously
fed from an oscillator (like a bowed string), they will swing together,
producing a harmonic overtone series; if not (like a plucked string),
they can swing separately, producing an inharmonic spectrum.
Hans
LJS
All good stuff. And the site is also very good. I may have stumbled
upon it before, but I apologize for not making my question clear.
Don't feel bad, I have yet to run across one that seems to grasp what
I am asking unless they tried to make up an answer. There may not be
an answer and there may be some basic obvious answer that evades me,
but if one is interested in understanding why some orchestrations work
and others do not, the question I am trying to pose is extremely
relevant. The answer may be in one of the orchestration books that are
common, I admit that although I have actually not done a lot of
reading on orchestration in a book setting. I listen to the
combinations and studied orchestration from a very aural perspective.
So I will try a different slant.
As I listen to the harmonics on a stringed instrument, I notice that
each harmonic seems to have a unique timbre that is somewhat "thinner"
in sound as you go to the higher harmonics on a string instrument.
Bass players often tune their instrument tuned in 4ths by playing the
A string double octave harmonic (element 8 I believe) along with the D
string's harmonic of its 5th to get better accuracy. I used this same
principle trying to tune up my Aud when I lived in Moroc (The
atmosphere there is very conducive to listening to the tunings for
some reason!) and I played around with different combinations of
common tones from one string to the other with the harmonics.
It seems to me that on the string instruments, these different
overtone versions of the same pitch have different timbres and the
higher up in the series (the higher element of the Harmonic Series)
you loose all the overtones below that harmonic.
In a low string, the 4th element (2x 8va) will still contain the
elements 4, 5 6 7 and 8 but will not have its "bass" notes of first
three elements of the series. IF you play the low 5th harmonic, you
get a 6/4 quality of sound from the tone as the 5th is the lowest
sound heard so there is not that lower fundamental to give it the
stronger ROOT feeling. The same is not so true with the Octave
harmonic as this tone is the bass note and even though it is higher
then the fundamental, it still IS the root so it does have a more
stable or tonic quality to it (or dominant, depending on who you
ask :-)
Now this is the theory part as I don't know of any instrument that
uses these principles to produce sound BUT this is where my question
comes in:
Assuming that what I hear is true (and the absence of these tones when
the string is scanned with a strobe) then when you play a wind
instrument, you produce the tone by blowing to vibrate the lips, reed
or stream of air in sympathy with the length of pipe or the distance
of the holes in the pipe that will be sympathetic with one of the
overtones so when you play a C on the 3rd space Treble clef on the
trumpet, does the G and the C overtone as well as the actual
fundamental of the pipe length (or half length as the case may be)
exist at all?
The answer to this, I think is "very likely not. BUT my question is
about the tone actually played and what overtones are ABOVE this 3rd
space C.
DOES this tone have as its next highest harmonic the octave C (two
ledger lines) and then the high G above that OR
DOES this tone have its next highest harmonic to be the 4th space E
then G then the A/Bb and then the 2 ledger line C?
This is what I am trying to know for sure. In the lower register, the
Middle C on the trumpet would then have as its next highest harmonic
the 2nd line G on the Treble clef.
If, as with the harmonics on the string, this is the case, then the
orchestrator would have a very valuable understanding of why one
combination of instruments voices one way will sound great and a very
slight variation may not sound well at all. Usually when I hear people
talk about orchestration, they seem to assume that each tone is a
fundamental tone complete with the harmonic series chart. If the wind
instruments do not behave in that manner, then the assumptions based
on their perception of the nature of the sound must be compromised.
I hear it to be so. I can't prove that this is correct or incorrect. I
am looking for some documentation or research that addresses this
question.
Too long? Yes I know, but maybe this will explain the question better
and I can think of an easier way to explain what I am asking! ;-)
LJS
Hans Aberg
Yes, too long. When you play on a harmonic, the partials probably
weaken, producing a thinner sound. And the site mentioned that the
clarinet was inharmonic beyond the 7th partial in the high and low
parts. So there soulc be all sorts of phenomena causing the effects.
Better looking at this site or others like it, to see what is actually
measured up.
Hans
LJS wrote:
>> You have a site here with a lot of acoustics information:
>> http://www.phys.unsw.edu.au/jw/clarinetacoustics.html#spectrum
>> http://www.phys.unsw.edu.au/jw/basics.html
>>
>> As you can see, that the real behavior of the clarinet is quite
>> different from the simplified model of only having odd partials.
>>
>> But suppose you have a pipe which only produces odd partials f, 3f, 5f,
>> ..., over a fundamental frequency f, and overblows so that the 3f is
>> the fundamental. Then as it is the same pipe, the overtones must be from
>> the original series of odd numbers times f, but it must also swing
>> together with the oscillator that generates them, which are 3f, 6f, 9f,
>> 12f, 15f, ..., but 6f and 12f are not possible since not in the original
>> series, so this is 3f, 9f, 15f, ... If you put g = 3f, this is g, 3g,
>> 5f, ... In other words, it has the same type of spectrum.
>>
>> Roughly what is going on here is that the tone will behave as a set of
>> independent oscillators. If there is a way to feed them, they will
>> swing. If they are sufficiently strongly coupled, like when continuously
>> fed from an oscillator (like a bowed string), they will swing together,
>> producing a harmonic overtone series; if not (like a plucked string),
>> they can swing separately, producing an inharmonic spectrum.
...
LJS
> Yes, too long. When you play on a harmonic, the partials probably
> weaken, producing a thinner sound. And the site mentioned that the
> clarinet was inharmonic beyond the 7th partial in the high and low
> parts. So there soulc be all sorts of phenomena causing the effects.
> Better looking at this site or others like it, to see what is actually
> measured up.
>
> Hans
Well, I don't think you understand the question. I am sorry that I
can't be more clear. I do thank you for your time.
But you do say that you think in the harmonics that the partials
weaken when you play the harmonics. I don't see how this could be
true. When you put your finger (or slide bar) over the octave partial
(or halfway through the string. There is NO fundamental left in the
tone. This is true at least for the string. The entire length of the
string can not vibrate because your finger is stopping it. The string
is vibrating in two parts and there is not the one long string
vibrating. When you put your finger on the third of the string, the
lowest note vibrating on the string is 1/3 the length or the 5th above
the octave. There is not those other two notes below it that are
being produced by the string.
Because you stated this, and because of your statement about these
tones being weakened, I realize that I am not clear with my statement.
If, however, you have some documentation or some logic concerning
these tones that are present in the open string when a harmonic is not
being played, I would really like to hear or see it.
Although the site you sent is very good, it does not address my
question at all as far as I can see. I have looked at many sites and
have yet to find anyone addressing this question. Thank you for your
time, but if you can't see what I am talking about, then I will
continue my search in other places.
Thanks for your time. If you are interested, I will try to make it
more clear but otherwise, I do not want to start a circular argument
when you do not understand my question and I am not capable of making
it clear for you.
Thanks.
LJS
Hans Aberg
> On Jan 13, 8:27 am, Hans Aberg <haberg_20080...@math.su.se> wrote:
>> Yes, too long. When you play on a harmonic, the partials probably
>> weaken, producing a thinner sound. And the site mentioned that the
>> clarinet was inharmonic beyond the 7th partial in the high and low
>> parts. So there soulc be all sorts of phenomena causing the effects.
>> Better looking at this site or others like it, to see what is actually
>> measured up.
> But you do say that you think in the harmonics that the partials
> weaken when you play the harmonics. I don't see how this could be
> true. When you put your finger (or slide bar) over the octave partial
> (or halfway through the string. There is NO fundamental left in the
> tone. This is true at least for the string. The entire length of the
> string can not vibrate because your finger is stopping it. The string
> is vibrating in two parts and there is not the one long string
> vibrating. When you put your finger on the third of the string, the
> lowest note vibrating on the string is 1/3 the length or the 5th above
> the octave. There is not those other two notes below it that are
> being produced by the string.
It is best to actually measure it up. - You can write to those on the
site, if you so like.
Here is how I think about it: the partials act as independent
oscillators, that need energy to oscillate, and also can couple or be
decoupled. But the higher oscillators have more resistance in them. So
if you go play an over on a partial, it partials has also proportionally
more difficult to oscillate. This is my guess.
In addition, the instrument departs from being one dimensional. This is
what is causing inharmonicity. When coupled, the site said they will
produce an average frequency. But with larger inharmonicity, that may
steal more energy, and they may find it harder to even to couple -
producing the inharmonicity in the clarinet.
Hans
LJS
I can see that. It seems to coincide with the way I hear them. I don't
know what an "over" refers to, but I can see the partials as being
independent entities. This would be fairly obvious when looking at the
trombone and the trumpet. One usually plays through 8 partials in the
normal repertoire. Your lip buzzes to activate a particular partial.
Not a group of partials, but will buzz on any partial that is in the
series for that length of pipe. AND this is VERY close to what I am
looking to understand.
If you play the same part on the trumpet and the trombone an up a
partial (octave) to be in unison with the trumpet, even though they
are playing the same frequency, both on a brass instrument etc, but
there is no chance that you would confuse which instrument was which.
the difference in timbre is really quite obvious. The trumpet will
have a different partials sounding louder and softer then the other
because of the fewer bends in the tubing as the fundamental doesn't
really like to vibrate around corners, so each partial vibrates
independent of the others depending upon the way the pipe is twisted
from a pure straight tube. This is another area of agreement with what
I hear and your independent entities. But my question is about the
partials inherent in the length of pipe that would resonate a tone
below the vibration of the lips.
If you play a low C on a trumpet, you have the overtones of the G C E
G A/Bb C etc. sounding in the timbre of the instrument. The
Fundamental Low C is missing because it can't make it through the
bends of the pipe.
But if you play an open G, the question is what will be above and
below (or not) this open G frequency?
I hear it as NOT having either the fundamental or the first octave in
the shape of the tone. But from this tone, What comes next?
If this G is a FUNDAMENTAL of its own, the overtones would seem to be
a G octave, then D G B D E/F G etc. as its upper partials BUT
My question is: Will the OTS above this note be the same as with a
string's OTS when physically stopped with the finger and have this
Open G with the tones C E G above it instead.
On the same instrument with the same bends and size and all the
variables will be negated and I don't see how the tones of D and F#
would resonate well with the vibrating tone being on a G. I hear too
much of the M6 in this open tone to allow me to think otherwise unless
I can see how it can be another way.
Again, this is important as an explanation as to why a certain
combination of instruments mix with other instruments.
>
> In addition, the instrument departs from being one dimensional. This is
> what is causing inharmonicity. When coupled, the site said they will
> produce an average frequency. But with larger inharmonicity, that may
> steal more energy, and they may find it harder to even to couple -
> producing the inharmonicity in the clarinet.
>
> Hans
Thanks for the comment about "independent entities", in practice they
do seem to be that way to me. On the inharmonicity and other factors
that affect timbre is walking on a slippery slope. I am not saying
that this is not a factor, but like the bends of the pipe in the
brass, the myriad of factors in the instruments like the flute or oboe
and bassoon etc to allow these things to divert the discussion. They
are all important of course, but except for a really extraordinary
skew any of these "variables", everything will still pretty much work.
A variation of some sort may make things a bit rough, but thanks to
"Training" (spelling?), these things will work their selves out. There
is not much that should be able to change a notes OTS entirely. These
other dimensional aspects of the instruments ARE important, but they
would not really change the underlying structure of the OTS. The
amplitude of some "independent" partials may be affected, but the
same partials would remain. My question is "what partials remain?"
Thanks,
LJS
Hans Aberg
>> It is best to actually measure it up. - You can write to those on the
>> site, if you so like.
If you have a sound file, you can use the programs like this for free one:
http://www.klingbeil.com/spear/
In this program, you can even change the partials and listen to the change.
So it would be easy to play and record a note of an instrument and check
what it displays. One can the export the spectral data as numbers. This
method may not be ideal, but there are other such programs.
>> Here is how I think about it: the partials act as independent
>> oscillators, that need energy to oscillate, and also can couple or be
>> decoupled. But the higher oscillators have more resistance in them. So
>> if you go play an over on a partial, it partials has also proportionally
>> more difficult to oscillate. This is my guess.
>
> I can see that. It seems to coincide with the way I hear them. I don't
> know what an "over" refers to, ...
As when blowing over - feeding all the energy to the partial, so that it
acts as fundamental.
> ...but I can see the partials as being
> independent entities. This would be fairly obvious when looking at the
> trombone and the trumpet. One usually plays through 8 partials in the
> normal repertoire.
Blatter says that a talented player can reach up to the 16th partial on
some brasses. Flutes only up to 5th partial (in the virtuoso range).
> Your lip buzzes to activate a particular partial.
> Not a group of partials, but will buzz on any partial that is in the
> series for that length of pipe. AND this is VERY close to what I am
> looking to understand.
>
> If you play the same part on the trumpet and the trombone an up a
> partial (octave) to be in unison with the trumpet, even though they
> are playing the same frequency, both on a brass instrument etc, but
> there is no chance that you would confuse which instrument was which.
> the difference in timbre is really quite obvious. The trumpet will
> have a different partials sounding louder and softer then the other
> because of the fewer bends in the tubing as the fundamental doesn't
> really like to vibrate around corners, so each partial vibrates
> independent of the others depending upon the way the pipe is twisted
> from a pure straight tube. This is another area of agreement with what
> I hear and your independent entities.
Flutes don't have much partials, so might check if the timbre is more
"fluety" in the absence of measuring the partials.
> But my question is about the
> partials inherent in the length of pipe that would resonate a tone
> below the vibration of the lips.
I think it is not possible for those to oscillate, but if the
oscillators are coupled, they will be weak. I saw a flute spectrum I
think it was a long time ago, and it had a lot of sporadic, but very
weak, partials. They may be associated with the breathy character of the
sound.
So must perhaps look for a stricken instruments, where the oscillators
can decouple.
One experiment is taking a piano, and press the the damper pedal. The
press one key somewhere in the middle, and damper its strings shortly
thereafter. Then continue with that on other strings, to see what
partials you have. For example, use the hand or even the arm to damper
all strings above the original one. I think you may hear some of the
lower notes vibrate, but perhaps on a partial.
When striking a timpany, one suppresses a partial by striking the
membrane n a special way. On a gamelan gender, perhaps they do the same,
because I looked at the spectrum and found what appeared very weak
partial one octave below the fundamental. It also had a very weak
partial at about 7.5.
So it may not be impossible, but they would be very weak. Perhaps acting
as giving the note a special character.
> If you play a low C on a trumpet, you have the overtones of the G C E
> G A/Bb C etc. sounding in the timbre of the instrument. The
> Fundamental Low C is missing because it can't make it through the
> bends of the pipe.
>
> But if you play an open G, the question is what will be above and
> below (or not) this open G frequency?
So the general behavior will be that you will only have partials
multiples of G, as the other coming from the C or the fundamental below
will be suppressed: the oscillators will be coupled, so if they get out
of phase, the one which is fed the energy will discourage that.
The other partials, multiples of the fundamental, if present at, will be
very weak. But you will have to measure up the spectrum to see that.
> I hear it as NOT having either the fundamental or the first octave in
> the shape of the tone. But from this tone, What comes next?
>
> If this G is a FUNDAMENTAL of its own, the overtones would seem to be
> a G octave, then D G B D E/F G etc. as its upper partials BUT
>
>
> My question is: Will the OTS above this note be the same as with a
> string's OTS when physically stopped with the finger and have this
> Open G with the tones C E G above it instead.
They way I have assumed it to be is that when you play the G, you just
inherit the spectrum of the partials that are multiples of G. If there
is anything else at all, that is sporadic and very weak.
There is a difference though, and that the energy is fed it the G and
not the C's below it. So perhaps it even amplifies it relative its
partials, and makes the timbre even thinner.
There might be other factors due to human hearing: the ear is most
sensitive to dynamics in the 2 - 5 kHz range. So the higher partials may
move out of this region when blowing over, making it sound more thinner
because of that.
And the human ear starts to not hear the relative frequencies somewhere
at 3.5.kHz, at about A7 if A4 = 440 hz. I do not know if that is a part
of it, but one should perhaps take consider it as a part of an
investigation.
...
> Thanks for the comment about "independent entities", in practice they
> do seem to be that way to me. On the inharmonicity and other factors
> that affect timbre is walking on a slippery slope. I am not saying
> that this is not a factor, but like the bends of the pipe in the
> brass, the myriad of factors in the instruments like the flute or oboe
> and bassoon etc to allow these things to divert the discussion.
The before mentioned site said that the inharmonicity beyond the 7th
partial in the clarinet was in the low, chalumeau register is due to the
shape of the bell (not the bore, this time) and in the high parts
register due to the open holes.
So those phenomena are certainly part of the sound production.
> They
> are all important of course, but except for a really extraordinary
> skew any of these "variables", everything will still pretty much work.
> A variation of some sort may make things a bit rough, but thanks to
> "Training" (spelling?), these things will work their selves out. There
> is not much that should be able to change a notes OTS entirely. These
> other dimensional aspects of the instruments ARE important, but they
> would not really change the underlying structure of the OTS. The
> amplitude of some "independent" partials may be affected, but the
> same partials would remain. My question is "what partials remain?"
Apart from the main picture I gave above, some very weak partials that
must be measured up to using a spectrum analyzer.
Hans