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Re: [Phys-L] sound

_The Science of Sound_ by Thomas Rossing and _The Physics of Musical Instruments_ by Fletcher and Rossing are full of information understandable by physics-minded people. Non-scientists will be terrified by them. They need something along the lines of books by Berg & Stork or Hall.

As Kyle said, there is a reflection at the open end which creates a feedback pulse to the lips, creating a "lock-in" between the resonant frequency of the tube and the driving frequency of the lips. The flare of the bell allows the reflection point to drift. Different flare rates of the bell create different overtone intensities, affecting the "tone" of the instrument. It also affects the intonation of the notes and the ability to "lip up" or "lip down" a tone (play it slightly sharp or flat). The flare and the bore together affect how quickly the correct pitch is achieved and how stable the pitch is. The flare also modifies the overtone frequency profile to mimic an open pipe with integer overtones. Without the bell, it would be a single-end closed pipe with odd integer overtones.

A Bb standard trumpet generally plays a Bb below middle C (middle C on its score), but that is not the fundamental of the horn, it's the 2nd partial (1st overtone). The "pedal tone" is the fundamental. Beginning trumpet players find that they play (on their transposed music) C-G-C in open position, which is the n=2,3,4 of the series. Same behavior for trombones.

French horns are much longer tubes, so their normal playing range begins in even higher overtones. That's why there are so many closely-spaced notes in a fixed valve position, and early horns didn't even use valves. I have a recording of Handel's Water Music which has valveless horns. The intonation isn't perfect, but the technique of the players is phenomenal.

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of Forinash III,
Kyle
Sent: Friday, April 12, 2013 11:08 AM
To: <phys-l@phys-l.org>
Subject: Re: [Phys-L] sound

Hi

There are (at least) three additions to make regarding the bugle. One is the
mouthpiece is a small cavity with its own Helmholtz resonance. This has an
effect on the strength of the frequencies available to the rest of the tube.
The second is the impedance mismatch at the open end of the horn. To set
up a resonance some sound has to reflect from the open end of the horn.
The gradual change in diameter reduces the mismatch (allowing some sound
to leave the horn which is desirable and why brass instruments are louder
than instruments with smaller horns) but doesn't eliminate it (otherwise no
resonances would be possible). Different wavelengths (due to different lip
buzzing driving frequencies) reflect at different diameters so different
frequencies 'see' a different length tube. These two effects apply to the
fundamental as well as harmonics. Part of the 'bright' or 'brassy' sound of a
brass instrument has to do with the shift in higher overtones from harmonic
to not exactly ha rmonic.
Also, a closed ended tube only has odd harmonics present in the first place.

I am in the process of constructing an online text for an introductory sound
course and would appreciate any suggestions:
http://homepages.ius.edu/kforinas/S/Introduction.html

kyle


------------------------------

Message: 15
Date: Fri, 12 Apr 2013 07:21:22 -0400
From: "Anthony Lapinski"
<Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>>
To: phys-l@phys-l.org<mailto:phys-l@phys-l.org>
Subject: [Phys-L] sound
Message-ID:
<fc.000f54740994abca000f54740994abca.994acab@pds.org<mailto:fc.000f547
40994abca000f54740994abca.994acab@pds.org>>
Content-Type: text/plain; charset=UTF-8

Does anyone know how a bugle produces different notes (as it has no keys,
valves, slides, etc.)? I know the instrument when played is physically closed,
but it behaves like an open pipe due to the bell's conical shape.
So the harmonic series is fn = nv/2L The length of the instrument is constant,
so does the player just blow/buzz his/her lips faster? or with a higher
frequency? That changes the harmonics/frequencies, but does that change v
in the equation? I thought v was the speed of sound in air (343
m/s) for brass instruments. I'm a bit confused with some of the finer details
of this "simple" instrument.



------------------------------

Message: 16
Date: Fri, 12 Apr 2013 08:01:05 -0400
From: Marty Weiss
<martweiss@comcast.net<mailto:martweiss@comcast.net>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] Car repair
Message-ID: <BB09D706-CCFD-4847-B4F2-
98389E97201F@comcast.net<mailto:BB09D706-CCFD-4847-B4F2-
98389E97201F@comcast.net>>
Content-Type: text/plain; charset=us-ascii

two things here: first, my story is to relate that you cannot modify or repair a
car now like we did back then. Few people even back then took a whole car
apart, but the story goes to show that you could if you wanted to... that
doesn't exist any more. Maintaining cars then meant the brakes (still can
do), the carb. (who will tackle fuel injectors and the electronics that go with
them??? not too many people can or want to do that.), alternator? ( can you
stil take that off and restore it back in an hour like the guy in college? I doubt
it.). The list goes on and on of things that we used to do fairly easily that
simply cannot be done any more.... Take the radio. I could take an old radio
out of my old Rambler, modify the dash to accept a new radio, install it, wire
it, and listen to rock and roll in a couple of hours. Could you do that now?
Second: Well, among many young people the interest is still in cars, but they
have realized that they cannot simply strip down a car like the old days. Sure
I know two sons of friends who can do the brakes on their mom's Ford
Explorer in the yard. But when it comes to engine work? They take it to their
place of business... one works for PepBoys and the other works for a Ford
dealer.. both are highly trained mechanics. They used to take apart and out
together simple engines in their parents' garages, but now? They must go
for training every six months to maintain a certification to work on cars at the
shop.
Someone in this thread stated that the basics of the automobile are the
same... yes, it's still the internal combustion engine and the brakes and
steering. But I maintain that it has become so complex that if you screw up
one thing the whole thing is messed up. If you want to study a manual and
buy a bunch of equipment to find and replace a tiny chip that runs a whole
engine.. fine, be my guest. I, for one, and thousands like me will find and
take my car to a mechanic who is well trained, studies his craft, and can be
trusted to do the job right and not leave me stranded on the turnpike
because a chip malfunctioned.

On Apr 12, 2013, at 6:07 AM, Matt Coia wrote:

So, are we talking modifying or maintaining vehicles now? I think the things
you talk about are still possible but the number of young folk who would
actually WANT to yank their alternator from their car has dwindled. Where
the primary interest of the youth in the 50's/60's might have been cars, today
we could probably argue that the primary interest of our current youth
revolves around computers/gaming/social media. It's a different mindset.




------------------------------

Message: 17
Date: Fri, 12 Apr 2013 08:15:51 -0500
From: Paul Nord <paul.nord@valpo.edu<mailto:paul.nord@valpo.edu>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] sound
Message-ID: <DAC0168C-B8CB-4690-9764-
1562199B0FE5@valpo.edu<mailto:DAC0168C-B8CB-4690-9764-
1562199B0FE5@valpo.edu>>
Content-Type: text/plain; charset=us-ascii

Excellent question.

Yes, just as you suspect, there are multiple resonances in the bugle. The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There may
be a small range around those pitches which will sound. But, principally you
are limited to those notes because of the fixed length of the instrument. On
a valved brass instrument like a trumpet the valves cut off or add lengths of
pipe. Each valve position allows a different harmonic series to sound.

See:
Bugle - Wikipedia, the free encyclopedia

And compare those notes which the bugle can play to the melody for
Reveille or Taps. These songs are played on just these notes because each is
written for the bugle.
Reveille - Wikipedia, the free encyclopedia

Paul


On Apr 12, 2013, at 6:21 AM, "Anthony Lapinski"
<Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>> wrote:

Does anyone know how a bugle produces different notes (as it has no keys,
valves, slides, etc.)? I know the instrument when played is physically closed,
but it behaves like an open pipe due to the bell's conical shape.
So the harmonic series is fn = nv/2L The length of the instrument is constant,
so does the player just blow/buzz his/her lips faster? or with a higher
frequency? That changes the harmonics/frequencies, but does that change v
in the equation? I thought v was the speed of sound in air (343
m/s) for brass instruments. I'm a bit confused with some of the finer details
of this "simple" instrument.

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l



------------------------------

Message: 18
Date: Fri, 12 Apr 2013 10:32:29 -0400
From: "Donald Polvani"
<dgpolvani@verizon.net<mailto:dgpolvani@verizon.net>>
To: <Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>>
Subject: Re: [Phys-L] sound
Message-ID:
<000601ce378a$8ff25140$afd6f3c0$@verizon.net<mailto:000601ce378a$8ff2
5140$afd6f3c0$@verizon.net>>
Content-Type: text/plain; charset=US-ASCII

Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle. The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There may
be a small range around those pitches which will sound. But, principally you
are limited to those notes because of the fixed length of the instrument. On
a valved brass instrument like a trumpet the valves cut off or add lengths of
pipe. Each valve position allows a different harmonic series to sound."

As an old (high school level) trumpet player I can assure you that the player's
lips must vibrate at a higher frequency to achieve higher notes on a bugle. A
trumpet becomes, effectively, a bugle, if the player doesn't make use of the
valves. This is achieved by stretching the muscles around the lips,
compressing the mouthpiece tighter against the player's lips, and blowing
harder. As a high school player limited to producing just a few notes above
"high C", I always admired leading classical trumpet players like Maurice
Andre and Winton Marsalis who could play extremely high notes.
However, even they can be seen to be struggling when producing the
highest possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012



------------------------------

Message: 19
Date: Fri, 12 Apr 2013 11:14:57 -0400
From: "Anthony Lapinski"
<Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] [SPAM] Re: sound
Message-ID:
<fc.000f54740994d3f9000f54740994abca.994d52d@pds.org<mailto:fc.000f547
40994d3f9000f54740994abca.994d52d@pds.org>>
Content-Type: text/plain; charset=UTF-8

Thanks for these responses. So what, then, changes in the equation fn =
nv/2L? Lips vibrate faster, so v changes? But I thought v = 343 m/s (speed of
sound in air). Or does n change, which creates the higher
frequencies/harmonics? What changes in that equation to predict which
frequencies are played on a bugle or other instrument where L is constant)?

P.S. I was a big fan of Maynard Ferguson, who could hit super high notes on
the trumpet. Saw him live in concert serveal times. Amazing!


Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org> writes:
Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle.
The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There may
be a small range around those pitches which will sound. But, principally you
are limited to those notes because of the fixed length of the instrument. On
a valved brass instrument like a trumpet the valves cut off or add lengths of
pipe. Each valve position allows a different harmonic series to sound."

As an old (high school level) trumpet player I can assure you that the player's
lips must vibrate at a higher frequency to achieve higher notes on a bugle. A
trumpet becomes, effectively, a bugle, if the player doesn't make use of the
valves. This is achieved by stretching the muscles around the lips,
compressing the mouthpiece tighter against the player's lips, and blowing
harder. As a high school player limited to producing just a few notes above
"high C", I always admired leading classical trumpet players like Maurice
Andre and Winton Marsalis who could play extremely high notes.
However, even they can be seen to be struggling when producing the
highest possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l




------------------------------

Message: 20
Date: Fri, 12 Apr 2013 10:36:50 -0500
From: Paul Nord <paul.nord@valpo.edu<mailto:paul.nord@valpo.edu>>
To: Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org>
Subject: Re: [Phys-L] sound
Message-ID: <185743B0-1F9E-4643-BAD7-
E2524601C67C@valpo.edu<mailto:185743B0-1F9E-4643-BAD7-
E2524601C67C@valpo.edu>>
Content-Type: text/plain; charset=us-ascii

Perhaps this is just a question of interpreting that equation.

It might be clearer to write it this way:
f(n) = n*v/(2*L)
where:
n is a positive integer
v is the speed of sound
L is the length of the pipe
f(n) gives you a list of resonant frequencies

As Don points out, you change your embouchure to adjust the driving
frequency of your lips. Only when this driving frequency matches one of the
resonant frequencies of the pipe will it produce a good sound. There is some
feedback from the sound in the pipe which helps to lock in the frequency of
your lips. That is to say, you feel your lips buzz against the air column and
that helps to cause the flapping of your lips to match a resonant frequency of
the pipe.

Paul


On Apr 12, 2013, at 10:14 AM, "Anthony Lapinski"
<Anthony_Lapinski@pds.org<mailto:Anthony_Lapinski@pds.org>> wrote:

Thanks for these responses. So what, then, changes in the equation fn =
nv/2L? Lips vibrate faster, so v changes? But I thought v = 343 m/s (speed of
sound in air). Or does n change, which creates the higher
frequencies/harmonics? What changes in that equation to predict which
frequencies are played on a bugle or other instrument where L is constant)?

P.S. I was a big fan of Maynard Ferguson, who could hit super high notes on
the trumpet. Saw him live in concert serveal times. Amazing!


Phys-L@Phys-L.org<mailto:Phys-L@Phys-L.org> writes:
Paul Nord on 4/12/13 at 9:16 am wrote:

" Yes, just as you suspect, there are multiple resonances in the bugle.
The
resonance which sounds is a function of the driving frequency. This means
that such an instrument can only play certain notes of the scale. There may
be a small range around those pitches which will sound. But, principally you
are limited to those notes because of the fixed length of the instrument. On
a valved brass instrument like a trumpet the valves cut off or add lengths of
pipe. Each valve position allows a different harmonic series to sound."

As an old (high school level) trumpet player I can assure you that the player's
lips must vibrate at a higher frequency to achieve higher notes on a bugle. A
trumpet becomes, effectively, a bugle, if the player doesn't make use of the
valves. This is achieved by stretching the muscles around the lips,
compressing the mouthpiece tighter against the player's lips, and blowing
harder. As a high school player limited to producing just a few notes above
"high C", I always admired leading classical trumpet players like Maurice
Andre and Winton Marsalis who could play extremely high notes.
However, even they can be seen to be struggling when producing the
highest possible notes on a trumpet.

Don

Dr. Donald G. Polvani
Adjunct Faculty, Physics
Anne Arundel Community College
Arnold, MD 21012

_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l


_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
http://www.phys-l.org/mailman/listinfo/phys-l



------------------------------

Subject: Digest Footer

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Forum for Physics Educators
Phys-l@phys-l.org<mailto:Phys-l@phys-l.org>
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------------------------------

End of Phys-l Digest, Vol 100, Issue 8
**************************************

---------------------------------
"It is not enough to observe, experiment, theorize, calculate and
communicate; we must also argue, criticize, debate, expound, summarize,
and otherwise transform the information that we have obtained individually
into reliable, well established, public knowledge."
John Ziman

Kyle Forinash
kforinas@ius.edu<mailto:kforinas@ius.edu>
http://homepages.ius.edu/kforinas




_______________________________________________
Forum for Physics Educators
Phys-l@phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l