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Re: [Phys-L] sound

Anthony,

There are several references that may help you out. Each has useful tidbits but I have not seen a completely coherent explanation in any of the standard texts that gives a simple explanation for the student and still satisfies the person truly knowledgeable in acoustical physics though some come close. Donald hall's "Musical Acoustics" chapter 13 isn't a bad place to start. Benade, "The Physics of Brasses" Scientific Amarican 1973 is useful. Fletcher and Rossing "The Physics of Musical Instruments" chapter 14 is excellent for a starting point - but not for the mathematically naive.

Keep in mind that a musical instrument is far different from a simple pipe. It is much like comparing apples and oranges. Still a good model is to start with a pipe, closed at the mouthpiece end, open at the other end. This gives odd harmonics. The trick is to move the harmonics around so they look like even harmonics. So, add a mouthpiece. The biggest effect is it adds a filter so the high frequency harmonics are reduced. Just as important it shifts the high harmonics down in frequency. Then add a bell. The bell operates on the lower frequencies and shifts them up. If you get the right combination, you get a series of harmonics that looks like on open pipe and the contraption becomes a musical instrument.

Dan


On Apr 13, 2013, at 12:00 PM, phys-l-request@phys-l.org wrote:

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: sound
Message-ID: <fc.000f54740994d3f9000f54740994abca.994d52d@pds.org<fc.000f54740994d3f9000f54740994abca.994d52d@pds.org">mailto:fc.000f54740994d3f9000f54740994abca.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