[Dixielandjazz] Trumpets and Cornets

[Craig I. Johnson]

Further, (or, to further confuse....)
There is an explanation I read that the cornet is (on average)  2/3 conical and 1/3 cylindrical whilst
the trumpet is the reverse.

THere is also an explanation that the cornet has 4 180 degree bends  in the major tube, where the
trumpet has 2. This explains the shorter appearance of the cornet. However,
this can be argued as there are various designs for the cornet that add even more
(one of the Conn cornets has a micro tuning slide whichis 90 degrees from the main
tube and is in itself a full 180 degree bend.)
(all the other 180 turns are similar in both horns as they are for adding lengths to the main
tube when the valves are pressed - so they don't enter into the above explanation.

I would guess that the brilliance of the trumpet is at least partly due to the more free standing
longer tubes of the trumpet vs. the cornet. (Free-er to vibrate, it would appear.) (Though more
modern cornets appear to be longer than the older ones, which would possibly blur the
tonal difference (except for the part of the tone due to the longer cone.  

 To emphasize this, think of a "herald" trumpet. where the only bends are the valve bends and 
the main tube is one long straight tube. These instruments,used largely for "fanfares" are even 
more brilliant sounding than a common cornet.

I have to correct my examples of of conical/cylindrical reed instruments as it would appear to me
that a clarinet is really conical rather than cylindrical though, if so,  it is a very long  cone.

Craig


On 6/9/2005 3:15:33 PM, Robert Smith (robert.smith at mitransport.no) wrote:
> Hello John,
> 
> As Craig says, the cornet is conical from the bell to the first moving
> part, as are all the other cornet-like instruments, e.g. tenor horn,
> euphonium, tuba.
> The trumpet, however, is based on a parabola (again from the bell back to
> the first moving part). If you draw a parabola, and then rotate it about
> the X-axis you will trace out the shape of a trumpet, and all trumpet-like
> instruments e.g. trombone, french horn, sousaphone.
> Both the normal trumpet and the normal cornet are concert Bb instruments,
> although both are made in other keys.
> In appearance, the trumpet is much longer than the cornet with sharper
> bends.
> 
> Cheers
> 
> Bob Smith
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