Talk:Brass instrument

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I have removed the "tenorshawm horn", on the grounds that I don't believe it exists (it was originally listed at list of musical instruments also, but has been removed from there). If anybody knows what one is, I'm dying to know, so lets hear about it! --Camembert

I suspect it's a tenor shawm, which was a medieval reed instrument, not a brass instrument. I think it's a "horn" only in the sense that an "English horn" is a horn. -- Someone else 02:40 Dec 8, 2002 (UTC)
I know of the shawm, but thought this must be something different, as it was placed under "brass". Writing a shawm article is one of those things on my "to do" list. --Camembert
Blessings upon you. I think a good title might be "Instruments that sound like a bleating goat"<G>. -- Someone else
Heheh - it's "strident", that's all. They had to have "strident" instruments in those days, because they hadn't invented the microphone yet ;) --Camembert

Contents

[edit] Query about "Category"

Is there any benefit to saying that "brass instruments" are part of the category "brass instruments"? I mean, maybe some systems of logic permit this, but I find it counterintuitive. Ok if I revert? Thanks, Opus33 19:51, 30 May 2004 (UTC)

Dunno - is it useful that clicking it takes you to a short list of everything else in the category? I quite like that. If that is a useful feature then it should stay. Like a lot of the changes that have happened it does move us further towards a nice unified approach to finding similar stuff, rather than huge individual articles' "see also" lists or depending on the article saying "the flugel is a bit like a horn and a bit like a trumpet and a bit like a cornet and not much like a cornetto etc etc" ... hmmm not sure. I know what you mean about the set logic approach, yes, but I do quite like the indexing benefits. --Nevilley 20:55, 30 May 2004 (UTC)
Thanks, Nevilley; I think you're right we should keep it. Cheers, Opus33 22:16, 30 May 2004 (UTC)

[edit] physics of the bell

people say that a bell shape amplifies sound, and they were used in phonographs, too. it doesn't seem likely to me that it could actually amplify, though, being just a passive piece of material in a specific shape. can anyone explain the (apparent) amplification? - Omegatron 03:35, Sep 4, 2004 (UTC)

Well, from what I have gleaned off the web, the bell/horn shape does amplify the sound, in that it increases the amplitude of the sound waves, although it does not introduce any enery into the system. This makes sense; as sound waves resonate in the horn, they travel from the small end to the big end. By the time they leave the horn their amplitude is as big as the bell. I am guessing that the flared bell gives kind of a cheat by increasing the amplitude a lot at the end. Also, the shape of the bell affects the sound in complicated ways that I know nothing about. In addition, the bell shape serves to focus the sound in a particular direction. Here is the Google search I did and two links to some explanations. Hope that helps, Merphant 14:20, 11 Nov 2004 (UTC)
Hmm.. still doesn't make sense to me.  :-) - Omegatron 14:24, Nov 11, 2004 (UTC)
Hmmm... Is it just a matter of more efficiently converting vibration into sound? The vibration that isn't converted into sound becomes heat? Probably. I am rusty on the physics, but I imagine it takes the same amount of energy/power/whatever to drive a 1 gm sphere as to drive a 1 gm plate. But the plate would move more air. Obviously some of your energy goes into "wind resistance" which I guess is the same thing as converting that energy into sound. But what becomes of the extra energy? Heat doesn't sound right. - Omegatron 04:32, Mar 14, 2005 (UTC)

128.83.101.89 05:55, 15 December 2005 (UTC)

I would not call a trumpet an amplifier, and here it is as I understand it from physics classes:

If the bell end of your trumpet were not flared, like the chopped off end of a pipe, most of what you would hear would be the fundamental frequency (at which your lips actually move), and then VERY LITTLE high pitched "white noise" produced by buzzing, sounding like a mellow hum. Experiment with hoses and pipes yourself. This is where the bell comes in. The white noise, through the tube, is converted largely to high-pitch, intertube reflecting standing waves that are only audible if the end flares out (so these waves that have bounced transversely can be directed foward). The fundamental pitch, on the other hand, is a longitudinal movement of the column of air, and only varies directly in volume with the amount of air blown.

The Magic in Action:

1.Buzzing (includes a fundamental pitch and whitenoise above it)--->

2.Mouthpiece resonance (exaggerates a select series of frequencies from the white noise)--->

3.Lead pipe to bell (like the mouthpiece, also exaggerates a select and infinite series of notes. here we trade off FAST air movement with minimal sound to SLOW air movement with maximum sound...ENERGY IS CONSERVED!)

4.Bell (high frequencies resonating and reflecting inside the tubing from your buzzing "white noise" are projected foward)

To justify the penultimate bullet, remember, that if the lips were flapping, but no air was moving through the column, it would be very quiet. Air movement is KEY to the sound (exactly like a whistle or a flute). Thus, in effect, we are trading fast air movement for loud sound. And while it is tempting to call this phenomenon "amplification," only a select series of pitches (from your buzzing) actually makes it out the bell. I think a more accurate name for the process would be "harmonic filtering." Calling a trumpet an amplifier is like calling a flute an amplifier...what does a flute amplify? Nothing. You channel white noise into vibration of an air column, beginning with FAST air movement and ending in slow air movement (conservation of energy).

What happens: My educated guess? The volume of the low fundamental frequency you are buzzing is, for the most part, "unamplified" in brass instruments. It varies directly with the amount of air blown. On the other hand, higher frequencies, once a significant volume level has been reached, "appear" to become disproportionately louder, when really, all that is happening is as the white noise from the lips vibrating increases, higher and higher notes in the harmonic are piled on top of eachother to create "constructive interference," as the highest pitches formed start becoming out of audible range. Any given frequency in a brass instrument (even if input by a sinewave-producing loudspeaker) reaches a maximum volume, and from then on, only an illusion of "getting even louder" takes place, when really, only new, higher modes in the vibrating air column are activated, with each of those attaining its own maximum amplitude as new frequencies are exponentially added above it from your lips slapping harder.

Hope you like my reasoning, Mike G

P.S. To those who want to know what "series of frequencies" I was referring to, [[1]].

128.83.101.89 05:55, 15 December 2005 (UTC)

The bell of a brass intrument functions in a similar way to a megaphone. It's the same as if you cup your hand over your ear. More of the sound waves are channelled in the direction that you want, toward the audience. Also, keep in mind that the entire instrument vibrates, so both the metal and the air inside the instrument. Feel the bell of a brass instrument while it's playing, this is more noticable on bass-instruments like the tuba. --edgester 00:46, 18 June 2006 (UTC)

[edit] Comments of a physicist

The purpose of the bell is in impedance matching, to maximise the energy transfer from the standing wave withing the instrument to the surrounding air. The principle, which is not explained in the impedance matching article itself, is that a gradual change in tube diameter (the bell) causes a gradual change in impedance. Gradual changes in impedance have improved energy transmission compared to step changes because the waves reflected back into the instrument tend to cancel each other out.

In this sense the bell is not an amplifier (this is indeed impossible with no additional energy input), but it does have an amplifying effect compared to no bell.

If no bell was on the instrument it would sound as bad as a simple piece of garden hose. The harsh 'white noise'y sound is heard in this situation because higher frequencies are more easily transmitted across an impedance step, in a mechanism analogous to the reduced bass response of smaller speakers. See Impedance matching#Acoustical matching.

At least thats what I understand from doing two years of degree level physics! I hope it helps... - Zephyris Talk 21:12, 7 November 2006 (UTC)

[edit] Is a mouthpiece essential to a brass instrument?

The first paragraph of this entry lists a mouthpiece as an essential part of a brass instrument. I disagree. A conch shell with the tip ground off has no need for a separate mouthpiece in order to be put into use as a brass instrument. Nor does the didgeridoo. Both instruments are, I believe, properly classified as brass instruments, since their sound derives from lip vibration causing oscillation of a column of air in a tubular or conical resonator. What makes an instrument "brass" is how its sound is produced, not what material it is made of -- as is already noted in the article -- nor the details of its construction, such as the presence or absence of a mouthpiece.

I will go ahead and edit the first paragraph, to address two related problems. First, the definition of brass instrument currently lists a mouthpiece as a defining feature of the type, which it is not, as is implicitly acknowledged later in the article by the listing of shofar and conch as brass instruments, even though these usually do not have mouthpieces. Second, the definition further specifies a cupped mouthpiece as a defining feature. This is even more clearly incorrect, as the mouthpiece of the French horn provides an obvious counterexample.
I will make two other modifications. I will make mention of the term labrosone, used as a synonym for brass instrument by Anthony Baines. I will also add didgeridoo to the list of other brass instruments. Rohirok 04:54, 13 Nov 2004 (UTC)

This depends on your point of view. If you like the edgy sound that brass instruments have, then yes, mouthpieces are necessary. They channel a wide column of air into a small one and "spill" it back into a larger air column, saving your lungs' air. However, most importantly, as I stated above, mouthpieces serve as a filter of lower frequencies and a resonater of higher frequencies, thereby altering the equalization of the white noise input by your lips. Without a bell, these high, bright frequencies would not be projected foward. Of course, without a mouthpiece, they would not be there in the first place (they would still be in the muddle of white noise from your buzzing). -Mike

[edit] pictures of brass instruments

[edit] Partials

I'm not sure it's really correct to say partials are so called "because it causes only a part of the tubing to vibrate (whereas at the fundamental the entire tubing will vibrate)."

My understanding (admittedly from 10 year past A-Level physics) is that there is still a standing wave over the whole tube, but there are more nodes (and anti-nodes) of vibration (where you could argue that there is no vibration, as either there is no pressure change over time at these points, or no displacement of air molecules from their rest position).

If there wasn't vibration over the who tube, I don't think you'd get much noise out of the end (no energy propagation?) David Underdown 14:49, 8 March 2006 (UTC)

A partial is the interval between any note or that note, used interchangeably, played without any keys pressed down. they get progressively smaller as you rise in pitch. form the pedal tone up, it is, over 1.5 octaves: octave, perf. 5th, perf. 4th, major 3rd, minor 3rd. from there ity gets very fuzzy o the brass player, for many fingerings work. so on a Bb horn it would go:

odd F D Bb F Bb Bb(pedal)

That's the basic musicality of it. at least on a trumpet/euphonium/tuba/trombone. I don't know the physics. Faramirtook 01:20, 11 July 2006 (UTC)

The concept of a harmonic only using part of the tubing is incorrect, the higher harmonics use the entire length of the tubing, but with more waves withing that length. The term 'partial' may originate from the wavelength of the wave being only part of the entire length of the tubing. - Zephyris Talk 21:18, 7 November 2006 (UTC)

[edit] Jazzophone

While reading the leaflet in a CD by Michel Portal and Richard Galliano (Blow up), I discovered the existence and sound of a rare brass instrument of the thirties : the jazzophone. I managed to find a couple of pics, which I linked to in the embryonic article I initiate about it. Since I'm not a brass player myself, can anyone simply cite it somewhere in the article in a more à propos way than what I would do? Thanks in advance. --171.16.2.3 11:24, 27 June 2006 (UTC)

[edit] Pedal tone

Deleted the section; wildly inaccurate and not so coherent. I don't think "Pedal tone" merits its own section, but we could possibly use a more complete description of how the overtone system works on brasses. --Rschmertz 00:41, 9 September 2006 (UTC)

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