Alto Euphonium
Posted: Fri Jul 15, 2022 4:56 pm
Let's say you wanted to make an alto euphonium from parts. By "alto euphonium", I mean a wide-bore conical instrument pitched a 4th or 5th above the euphonium. The alto euphonium would be to the euphonium as the alto horn is to the baritone horn. Not an alto flugelhorn, because those are typically as small or smaller in bore/bell size as alto horns, and are played with small flugelhorn or alto horn mouthpieces. Something that proportionally matches the euphonium in the same way that the alto horn matches the baritone horn. It would also ideally be fully chromatic like a 4-valve compensating euphonium.
The Besson Sovereign 950 tenor horn has a .466" bore and 8" bell, which are typical specs for a British tenor horn. The Besson Sovereign 955 baritone horn has a .543" bore and 9.25" bell. The bore is a bit larger than more traditional baritones (which are around .510" if I remember right), but perfectly within the standard bounds for a British baritone. Finally, the Besson Sovereign 967/968 euphonium has a .590" bore and 11" or 12" bell, which is very standard for a modern euph. Using those dimensions as reference, we see that a typical tenor horn is about .44-.77" smaller in bore than a typical baritone horn, and 1-1.25" smaller in bell diameter. So we could expect an alto euphonium to be around the same range smaller than a typical euphonium, which would put it at .513-.546" in bore and 9.75-11" in bell diameter. Obviously the taper of the instrument is a bit more involved than just the bore and bell size, but it's a good place to start.
With that in mind, what would you scavenge to go around making one?
The first donor that comes to my mind would be a marching baritone - specifically, one of the old Bach/Blessing designs that looks like a big cornet (and plays like one too...I marched one in high school and loved it). It has large-throated 10" bell and a great valve block. The bore is large at .560", and it might be too big be usable cut down to alto F or Eb, but it might work out great. In that case, you'd rotate the valves and leadpipe to be in bell-up configuration, cut everything way down to alto pitch, and add additional valves from another source. I'd try to find a couple of orphan .562" trombone rotors, or cannibalize .562" valves from an old American baritone or G bugle. Of course a 4-valve compensating valve set would be ideal, but there are pretty much none in the right size. There's the .540" set from the Wessex BR-144, but spending $1,670 to get a new BR-144 just to cannibalize the valves seems wasteful at best. So I think sticking to cheap non-compensating donor valves is a better bet.
There are advantages and disadvantages to making the instrument in either F or Eb, and I figure eventually you'd want to try it in both. But recently I was inspired by the Wessex Bubbie travel tubas, which have a 5th rotor that can be reversed. By default the instrument is in F with a typical long whole step 5th valve, but you can reverse the valve so that then the instrument is in Eb with an ascending 5th valve, making it chromatic in either key. I think this is the most efficient solution overall. However, if it came down to it that there were two 3-valve piston sets to use, you might as well make it 6 valves (3+3) if you can still make it comfortable to hold and play.
Alright, I'll admit it. This is not at all a hypothetical thought exercise, as I really do want to have someone build me an alto euphonium. Probably not any time in the immediate future, but not too far off either. So...how would you do it?
The Besson Sovereign 950 tenor horn has a .466" bore and 8" bell, which are typical specs for a British tenor horn. The Besson Sovereign 955 baritone horn has a .543" bore and 9.25" bell. The bore is a bit larger than more traditional baritones (which are around .510" if I remember right), but perfectly within the standard bounds for a British baritone. Finally, the Besson Sovereign 967/968 euphonium has a .590" bore and 11" or 12" bell, which is very standard for a modern euph. Using those dimensions as reference, we see that a typical tenor horn is about .44-.77" smaller in bore than a typical baritone horn, and 1-1.25" smaller in bell diameter. So we could expect an alto euphonium to be around the same range smaller than a typical euphonium, which would put it at .513-.546" in bore and 9.75-11" in bell diameter. Obviously the taper of the instrument is a bit more involved than just the bore and bell size, but it's a good place to start.
With that in mind, what would you scavenge to go around making one?
The first donor that comes to my mind would be a marching baritone - specifically, one of the old Bach/Blessing designs that looks like a big cornet (and plays like one too...I marched one in high school and loved it). It has large-throated 10" bell and a great valve block. The bore is large at .560", and it might be too big be usable cut down to alto F or Eb, but it might work out great. In that case, you'd rotate the valves and leadpipe to be in bell-up configuration, cut everything way down to alto pitch, and add additional valves from another source. I'd try to find a couple of orphan .562" trombone rotors, or cannibalize .562" valves from an old American baritone or G bugle. Of course a 4-valve compensating valve set would be ideal, but there are pretty much none in the right size. There's the .540" set from the Wessex BR-144, but spending $1,670 to get a new BR-144 just to cannibalize the valves seems wasteful at best. So I think sticking to cheap non-compensating donor valves is a better bet.
There are advantages and disadvantages to making the instrument in either F or Eb, and I figure eventually you'd want to try it in both. But recently I was inspired by the Wessex Bubbie travel tubas, which have a 5th rotor that can be reversed. By default the instrument is in F with a typical long whole step 5th valve, but you can reverse the valve so that then the instrument is in Eb with an ascending 5th valve, making it chromatic in either key. I think this is the most efficient solution overall. However, if it came down to it that there were two 3-valve piston sets to use, you might as well make it 6 valves (3+3) if you can still make it comfortable to hold and play.
Alright, I'll admit it. This is not at all a hypothetical thought exercise, as I really do want to have someone build me an alto euphonium. Probably not any time in the immediate future, but not too far off either. So...how would you do it?