Re: [Phys-l] musical instruments

[chuck britton <cvbritton@mac.com>]

The lowest note on a brass instrument is often called the 'pedal 
tone' (for reasons that I cannot fathom), VERY rarely heard (and when 
you DO hear it - you understand WHY). More of a 'fart' than a tone.

I'm interested in these technical measurements for a compare and 
contrast of the trumpet vs the cornet.
The cornet has a flare that covers much more of the total length of 
the instrument.
Much more 'mellow' than the trumpet. How do the measured lengths 
compare? (For the 'standard' B-flat instrument).

Note the different lengths for the 'Baritone' and the trombone.
Both are (IIRC) B-flat instruments. i.e. no valves actuated or no 
slide extension will give a B-flat tone.
The 'Baritone' has a much longer flare (like the cornet) while the 
t-bone has a more abrupt 'bell' as does the trumpet.

Great application of basic physics - with a serious nod to the 'real 
world' of art and aesthetics.

At 9:13 AM -0400 4/7/10, Edmiston, Mike wrote:
> One source is Thomas D. Rossing's book: The Science of Sound.
>
> In the chapter on brass instruments he lists...
>
> Trumpet 140 cm
> French horn 375 cm
> Trombone 275 cm
> Tuba 536 cm
> Baritone 264 cm.
>
> Note two things about calculations of the fundamental frequency. 
> (1) The effective length of a tube, especially one that is flared, 
> is ambiguous.  The node or antinode at the "end" is not literally at 
> the end of the metal.  (2) For a narrow bore instrument a person 
> generally cannot play the fundamental frequency (which I call the 
> 1st harmonic).  Rather, the lowest normally playable note on a 
> trumpet is actually the 2nd harmonic.  So if you are trying to have 
> students match lengths with lowest playable harmonic the numbers 
> will be (1) slightly off, and (2) will also appear to be an octave 
> off.
>
> For the nitpickers... some people can blow the fundamental on a 
> trumpet, but it is indeed difficult and not generally considered to 
> be a playable note.