TromboneChat

jonathanharker wrote: Thu Jun 12, 2025 6:19 pm

bbocaner wrote: Thu Jun 12, 2025 2:15 pm It doesn't differentiate between, say, a baritone horn and a tenor Wagner tuba. Which I hope we'd all agree are different instruments.

Oh for sure, heh... I posted it in the spirit of how we were discussing how rubbish the standards and controlled vocabularies often are.

Imagine trying to describe/pigeonhole modern electronics using a 1950s electrical engineering vocabulary/glossary!

As hilarious as the organological discussions of this instrument are, we still haven’t any idea of what a tenor tuba is.

I think the term “tenor tuba” might be more helpful if we think of it in terms of its function, rather than its origins or familial relations. In a very rough comparison, it would be like the physiology of the instrument (its use and purpose) rather than its anatomy (what it looks like or where its located).

Kbiggs wrote: Fri Jun 13, 2025 2:12 pm As hilarious as the organological discussions of this instrument are, we still haven’t any idea of what a tenor tuba is.

I think the term “tenor tuba” might be more helpful if we think of it in terms of its function, rather than its origins or familial relations. In a very rough comparison, it would be like the physiology of the instrument (its use and purpose) rather than its anatomy (what it looks like or where its located).

Easy. It's this!

Kbiggs wrote: Fri Jun 13, 2025 2:12 pm As hilarious as the organological discussions of this instrument are, we still haven’t any idea of what a tenor tuba is.

To the contrary, we have too many ideas of what it is. None of them can plausibly be said to be "wrong" without adding specificity to the characterization. And when you do that, you rule out things that you (or others) don't really want to rule out. There are just multiple (and not unreasonable) senses to what "tenor tuba" can/may/should be taken to mean. Such is the nature of natural language, especially used in disparate environments, as a medium of technical analysis.

And there ARE limits. At least we're pretty sure that a tenor tuba isn't a tenor saxophone.

slipmo wrote: Wed Jun 04, 2025 9:55 am Had to get all of the potential uses covered gotta recoup the instrument cost any way you can!

How about potential players? There's a lot of 3+1 euphonium players out there with weak, uncoordinated pinkies. Maybe (over) engineer an optional linkage that goes from 4 to the left index finger?

I was actually trying to steer the conversation towards how this thing—tenor tuba, flicorno, blatweasel, whatever—is used. Examples:

• Spanishmarching bands: anyone have any English info about these? This seems to be an untapped DMA dissertation, or perhaps an article in HBS Journal.

• Strauss: Don Quixote

• Holst: tenor tuba or euphonium?

etc.

I'm curious as to what is sounds like and where it would fit in, say, a tuba choir. The bore and conical flare from the last U-bend to the bell seem to put it sound-wise between a cimbasso and a euphonium, but I'm just guessing. I would think this would sit atop a tuba choir as the highest and brassiest voice (relatively). It might be nice for some very light chamber stuff, or maybe ophicleide parts?

How does Cerveny make those oval bells? That would take a very fancy lathe. Can you make a bell without spinning it?

Ummm ... try throwing this at ChatGPT: "How are the curved bell sections on oval euphoniums made?"

It will also offer to show you pictures of the process.

GPT answers are unreliable until vetted by an expert, which I am not. But I put in your prompt, and it didn't clear anything up. It looks like it was written by someone who doesn't know the answer, but is faking it anyway.

AtomicClock wrote: Sun Jun 15, 2025 12:56 pm GPT answers are unreliable until vetted by an expert, which I am not. But I put in your prompt, and it didn't clear anything up. It looks like it was written by someone who doesn't know the answer, but is faking it anyway.

I thought the response seemed accurate, based on what I know about tube bending, and consistent with what I see in terms of the bell in my oval euph. But, hey, let's see what the experts here who've actually seen it done have to say.

It'd be perfect for Ein Heldenleben & Don Quixote, etc.

At the 3.50 mark.of this video, it shows the spinning on a saxophone bell in the Yamaha factory.

Oval Baritones would be spun similarly. Not shown in this video, but done in most factories, is the drawing of the bell onto the mandrel, before the flare is spun. Infact only the last 6-12 or so inches of the bell flare of a baritone would be spun.

I think the real question is how that curve is put on bell section (in both the saxophone case and the oval baritone case). And if the flare at the end is spun (which seems right), wouldn't that be done before the section is then curved into its final form?

So what would the sequence be? ...
1. create (straight) conical bell section.
2. Spin the bell flare.
3. Curve the bell section from base to flare
???

That all makes sense. But how is 3 accomplished? Ah!... I just found this: https://www.robbstewart.com/bending-tubing. So I guess that's how the sweeping curves are put into those oval baritone bells as well -- and the ChatGPT answer (though brief and without much detail) seems to be "vetted" by an expert.

See the 2.50 mark of this video



Bending a tenor tuba bell after spinning would be a real challenge! It "may" be done, but it would surprise me.

That is so cool!! However, I don't see any evidence of a seam in my oval baritone. Does that just get compressed away as a result of that swaging?

Is it yellow brass? The brazing material can be difficult to see on yellow bells. What brand is the horn?

It's a 1965-ish Amati.

hornbuilder wrote: Sun Jun 15, 2025 7:46 pm At the 3.50 mark.of this video, it shows the spinning on a saxophone bell in the Yamaha factory.

Thank you. Shortly after asking my question, I realized it stood for many familiar instruments as well. Imagine spinning a Sousaphone bell!

AtomicClock wrote: Sun Jun 15, 2025 12:41 pm How does Cerveny make those oval bells? That would take a very fancy lathe. Can you make a bell without spinning it?

oh they spin them, I've seen it done at Meinl Weston. They have multi-part mandrel that screws together and the bell is put on the lathe so that the flare turns straight and the tail wobbles around in the air. There's a cage that goes over the bell tail so they don't get hurt by it. And then they turn it around so that the tail spins straight and the flare wobbles around. They go back and forth between the two orientations until it's done.

hornbuilder wrote: Sun Jun 15, 2025 8:10 pm See the 2.50 mark of this video

This is essentially the way they do the oval baritone bells as well, although they aren't made in halves like this, but this video doesn't actually show the spinning.

ghmerrill wrote: Sun Jun 15, 2025 12:52 pm Ummm ... try throwing this at ChatGPT: "How are the curved bell sections on oval euphoniums made?"

It will also offer to show you pictures of the process.

That's NOT how it's done. You can bend a trumpet bell tail after it's been spun, you can bend a horn bell after it's been spun. You cannot bend an oval baritone bell after it's been spun.

bbocaner wrote: Mon Jun 16, 2025 10:35 am They have multi-part mandrel that screws together and the bell is put on the lathe so that the flare turns straight and the tail wobbles around in the air. There's a cage that goes over the bell tail so they don't get hurt by it.

I think I get this part and can visualize it. But it appears to assume that the tail is already curved. How, exactly is that curving accomplished? Using the technique of the two longitudinal halves that are swaged together?

And then they turn it around so that the tail spins straight and the flare wobbles around.

But what does this accomplish? If the tail spins straight, what is being done in this step?

Or does this all assume the original curved formation (in two parts) of the (longitudinal) curved bell section on a large mandrel?

Sorry, I'm just not seeing this.

hornbuilder wrote: Sun Jun 15, 2025 8:28 pm Is it yellow brass? The brazing material can be difficult to see on yellow bells. What brand is the horn?

YEP. Kanstul used something the exact same color as yellow brass for all of their brazing, so finding the seam on their yellow brass bells is quite difficult. I have to pretty much look at the reflection until I can see the line. On the kanstul I have with a rose brass bell, the brazing line is easy to see.

On all my other trombones that have a brazed seam, it's very easy to see.

tbonesullivan wrote: Mon Jun 16, 2025 11:12 am On the kanstul I have with a rose brass bell, the brazing line is easy to see.

Yeah, on my red brass Cerveny 781 tuba, the seems were evident.

ghmerrill wrote: Mon Jun 16, 2025 11:10 am I think I get this part and can visualize it. But it appears to assume that the tail is already curved. How, exactly is that curving accomplished? Using the technique of the two longitudinal halves that are swaged together?

No. I didn't see this done first-hand, but the bells I saw being made were one-piece bells with one seam.

This video doesn't show the entire process, but it does show him working on an oval baritone bell at 13 seconds and then hammering it at 17 seconds and then at 19 seconds it's already spun and he's just buffing it -- so they skipped A LOT, but you can kind of see where they are going with the hand hammering. I suspect there are a series of mandrels he hammers against where the curve is introduced (and it's just the last 8 inches or so on a oval baritone bell)

But what does this accomplish? If the tail spins straight, what is being done in this step?

you know, the more I think about it the more I think they weren't actually doing this, that this step might have been done with a series of tin rings like you see in the saxophone bell video. But either way, the idea is to get the bent tail of the bell smooth and reduced to the shape of the inner mandrel. And then the flare is done with spinning.

Muddying the waters perhaps, but at 1.20 or so in this video, Marcus Teinert talks about drawing seamless tapered tubing for tuba branches.



Getzen do similar for their student/step-up trombones.

bbocaner wrote: Mon Jun 16, 2025 11:56 am you know, the more I think about it the more I think they weren't actually doing this, that this step might have been done with a series of tin rings like you see in the saxophone bell video. But either way, the idea is to get the bent tail of the bell smooth and reduced to the shape of the inner mandrel. And then the flare is done with spinning.

Yeah, at least this makes more mechanical sense to me. It's the whole longitudinal bending of the conical section that seems most problematic to me. But brass is very malleable if you take it slowly and in small increments. You do need to be wary of work-hardening, or maybe anneal at a certain step (though I'm not sure that would result in a good fabrication process and result). Use of "dies" (and "progressive" dies) for brass forming has a long history.

Annealing happens "numerous" times in the fabrication of most parts on brass instruments. It is not a "one and done" type deal. And sometimes it is only a portion of the part that is annealed before the work is performed.

ghmerrill wrote: Sun Jun 08, 2025 9:03 pm

AtomicClock wrote: Sun Jun 08, 2025 8:53 pm Well, here in Taxachusetts, I just put in an ILL request for the copy at Berkelee.

I'd be really surprised if that works.

I just got the ILL. Now I just have to figure out how to read 500 pages in 4 weeks.

AtomicClock wrote: Mon Jun 16, 2025 7:36 pm I just got the ILL. Now I just have to figure out how to read 500 pages in 4 weeks.

I'm impressed.

I have thought about this for the last couple days and have (re)watched virtually all factory tours and similar stuff available. It's a pity but this step is always skipped. However my current thesis how it's done is as follows:
- The bell starts the same as every one-piece/"hand-hammered" bell, it is cut out from a flat brass sheet according to some template. It is brazed/seamed, the seam is rolled and the bell gets hammered into rough shape. confidence level: high
- including the bent. confidence level: medium, execution order might vary with the next steps.
- then the bell is spun over a mandrel. confidence level: pretty sure the bells are spun, execution order might vary
- the rest of the bell is formed using the tin ring method, probably there is a mandrel for the complete bell, curve included. So the tin ring can used into the spun section to make for a nice transition between the drawn and the spun part of the bell. confidence level: highly speculative, additionally the execution order might vary, maybe the curved part is drawn before the bell is spun?

Another completely different approach would be to make it a two piece bell consisting of the outer straight part (spun) and the curved inner part (tin ring method?) and then braze them together. I can't see any benefit though because I think it still must be somehow drawn/spun onto some mandrel after brazing for a nice transition. Tubas are made with this method and then spun after brazing.

addon: This is how the next part of the instrument (Anstoß) is bent in a very manual approach:

I'm so very happy I don't build tubas..

Nomsis. The order of operations is the bell is formed on the mandrel, including the bend. Then the bent tail is drawn, then the flare is spun. The drawn section and spun section over lap some, so the bent part does not get spun.
Bending with lead is Old School. It is still done in the smaller shops. There is a video of the Alexander company, showing both lead bending a bell, and freeze bending a bell. They also use hydro forming to finish their freeze bent bells. I expect they do the same for their Wagner tubas and baritones

AtomicClock wrote: Mon Jun 16, 2025 7:36 pm I just got the ILL. Now I just have to figure out how to read 500 pages in 4 weeks.

It's a fun read! By all means read it cover to cover if you want, but that's pretty hardcore – maybe start with a chapter that interests you, and work your way forwards or backwards, or look something up in the extremely well organised and thorough index at the back to get started. It's basically the tuba bible.

jonathanharker wrote: Wed Jun 18, 2025 10:56 pm It's a fun read! ...

How different is the 2nd edition from the 1st? The 1st seems to be much more readily available in more places.

ghmerrill wrote: Thu Jun 19, 2025 7:22 am

jonathanharker wrote: Wed Jun 18, 2025 10:56 pm It's a fun read! ...

How different is the 2nd edition from the 1st? The 1st seems to be much more readily available in more places.

It's much more detailed and has many corrections and new bits; the scholarship is more up to date (more about the history was known in 2000 than in 1978) and it is more than double in size (639 vs 303 pages).

Just saw this reel from Miraphone, bending oval tuba branches!

https://www.facebook.com/share/r/19URex642W/

Slipmo,
Could you post a video of it being played? I`m sure we`d all love to hear it.

Hmmm ... beefy Germans beating on forms and mandrels with hammers of Thor. Old school.

at least they're not bending with lead! Those branches are filled with an ice solution, which is "considerably" easy to manipulate than lead. These hammers are rubber, too, so perhaps not quite in the realm of Thor.. I know Alexander and Voigt use hydraulic forming after the bending occurs, I expect Miraphone do too.

hornbuilder wrote: Sun Jun 29, 2025 11:12 am I know Alexander and Voigt use hydraulic forming after the bending occurs, I expect Miraphone do too.

Yeah, but I bet it's an advantage to advertise "hand-hammered construction".

Is Cerrobend any better/easier than pure lead? Or are you including that in what you mean by "lead" (since it's close to 30 per cent lead) ? Clearly the ice offers some real advantages for brass instruments.

Hand hammering is still involved, even if hydraulics are used to finish the part.

In my experience, lead and cero are essentially interchangeable, from the workability perspective.

A tangent on a tangent:

Many years ago, Conn used hydraulic pressure to finish the insides of tubes after bending. I think it was used mostly on small crooks like you’d find on trumpets. Does anyone use that process anymore?

Yes. Many companies use hydraulic forming. Conn have used it for many, many years! It is used generally for larger, tapered crooks that cannot be balled out. The J bend on the Conn 62 for example. Tuba branches. Trombone tuning slide crooks. Alexander uses it on French horn bell tails.

Hydraulic forming is referenced in this video from 1937


Smaller cylindrical crooks (trumpet, horn, trombone valve section crooks) are bent then balled out.

What a terrific video - from 1937! So many craftsmen and artisans in Elkhart who spent their working lives creating these wonderful instruments. A time gone by, methinks.

Yes. But having said that, having pulled apart "a lot" of old Conn's, they weren't all exceptional quality. Plenty of misaligned parts, gaps under ferrules, and poor solder work . These were Peace Work employees, generally speaking, so the more "things" they got done, the better. They were still "factory made", after all. Yes, there were Craftsmen there, particularly in this video from the earlier years, but later on, in the 50's-60's onwards, there were many who were "factory line workers".
Seeing the footage of the Stenberg brothers is really neat, though! Those guys are legends! Real craftsmen!