TubeNet

Where are the keys for the other two valves hiding? I see the valves but no keys/buttons.

I'm guessing that these valves are "set by hand" before playing, as they put the cornet in different keys. It probably doesn't change keys on the fly like a (french) horn does.

MA

At one time I had a mellophone like that, C D Eb or F.

Yes, indeed. They are "set by hand" change valves to pitch the instrument in either C, Bb or A, so you twist the knobs on the valve to turn the valve. Yes, because pitch is proportional and not linear, when you change the main key, you have to adjust the individual valve slides. And because that changes the proportion of cylindrical to conical tubing, to say nothing of introducing different node and anti-node placements, they tend to function marginally well in one key and not well at all in the other two, and never the same key for two horns in a row.

And now for something completely different from that: an echo cornet, for extreme immediate dynamic changes.

http://www.horncollector.com/Cornets/Pi ... Cornet.htm" target="_blank

It has a change valve coming off the valve block into the shepard's crook so it either goes to the conventional bell or the inverted cone echo bell. Cost and the development of inexpensive effective mutes effectively killed it. But last summer I had the pleasure of playing an original Distin in high pitch with its original mouthpiece, and the tone, though not loud, was sweet and expressive to die for.