Crunching the Numbers on CBA

[Walker]

Hi all.

I know very little about the CBA! So I wanted to ask a question about one particular feature of the 5 row (C system) button accordion that has intrigued me.

It's to do with the 87 button (converter instruments) without cassotto, but with 3 (LMM) or 4 (LMMH) treble voices.

Okay, so it seems 5 row CBAs with 87 buttons tend to have rows of buttons: 17 - 18 - 17 - 18 - 17

Now, as we know, the number of buttons on the three outer rows (17 - 18 - 17) gives a total of 52 notes.

So, it has always been my understanding that there can be a variety of note ranges on a 87 button instrument ranging from 46 notes to 52 notes (depending on the number of dummy buttons).

Now, from what I have seen many 87 button instruments with converter but without cassotto have a depth of approximately 21 cm. This seems to be the case regardless as to whether they have 3 treble voices or 4 treble voices. The pattern seems to be that 3 voice instruments may often have 52 notes and 4 voice instruments may often have 46 (sometimes 47) notes.

So here is my question...

Does a 52 note, 3 voice instrument require 4 reed blocks (rather than 3)?

What is the 'cut off' number of notes on a button accordion treble before it generally has more treble reed blocks than 'voices'?

Hope that wasn't too painful to get through.

 

[petch]

I might be taking absolute nonsense here but I think a 64 note 4 voice CBA will still only have 4 reed blocks, so I assume a 3 voice 52 note will still be on just 3 reed blocks for simplicity

edit: I think I was misremembering, there are 6(?) blocks in a 64 note 4 voice...

 

[Walker]

Thanks @petch. I thought the big 64 note accordions had more than 4 reed blocks, otherwise they would be very long accordions.

I suppose it might alternatively be that a 3 voice or 4 voice accordion (with 87 button) have the same depth because the free bass reed blocks are dictating this dimension...

I'm sure all will become clear.

 

[losthobos]

I've had a couple of LMH accordions and considered popping out the H reed blocks to drop weight... can't quite remember why I didn't bother..I now have a LM box with a couple of growls on a couple of reeds so had a nosey inside....2 blocks of reeds but the interesting thing was that if laid horizontal the top reeds were bassoon, the ones below on the same block were Clarinet and on the block below opposite ie clarinet on top bassoon on bottom.....
Also some Italian CBA are configured inside same as piano reed layout ( a la galliano ) and have longer keyboards as opposed to french CBAs which have shorter keyboards but deeper boxes to allow an extra set of blocks....
Whoever opened up the accordion would have found it easier to open a can of worms...

 

[petch]

Thanks @petch. I thought the big 64 note accordions had more than 4 reed blocks, otherwise they would be very long accordions.

I suppose it might alternatively be that a 3 voice or 4 voice accordion (with 87 button) have the same depth because the free bass reed blocks are dictating this dimension...

I'm sure all will become clear.

Sorry, I'd updated to say it had more than 4. The picture in my head had 4 but I went through some photos on my phone (I'd taken some of the reed blocks) and can see there are 3 + whatever is in the cassotto (presumably another 3)

let's wait for someone who knows what they're taking about to join the conversation

I believe my standard bass accordion with 4 voices (musette, no cassotto) has 4 blocks with 46 actual notes (and some fake buttons) - surely they can squeeze another 6 notes on each block? I imagine the construction would be much simpler to keep each voice to a particular reed block

 

[debra]

There are some special instruments, like the largest Hohner button accordions with 56 notes that fit 28 reeds on a single reed block (side) by using ultra narrow reed plates. But barring that, the largest button accordions the spread all there notes over just two sides of a reed block tend to have 46 or 47 notes, with perhaps an exception going up to 49 but not more than that.
So, accordions with 52 notes or more generally spread the notes over 3 reed block sides. As a result, a 4 voice instrument with 52 notes or more tends to have 6 reed blocks whereas one with 46 notes has 4 reed blocks. A 3 voice instrument with 52 notes or more requires 9 reed block sides, meaning 4 reed blocks plus a single-sided block, whereas a 3 voice instrument with 46 notes requires just 3 reed blocks.
Of course there are exceptions for everything. I have a small (60 bass) Weltmeister (convertor) accordion that is 2 voices with 42 notes, but it does not have the 42 notes spread over two reed blocks (21 notes each) but spread over three shorter reed blocks (14 notes each) in order to fit in the small box.
The largest accordions have 64 notes and 4 voices, meaning they have 6 reed blocks (4 with 21 notes and 2 with 22 notes).

 

[Walker]

surely they can squeeze another 6 notes on each block?

Hey petch, maybe you can make that suggestion next time you're in Castelfidardo.

I think it's fascinating that not all is as it first seems...

So if I am not mistaken, following @debra's kind clarification on the 87 button CBA:

46 notes & 3 voices = 3 reed blocks required
46 notes & 4 voices = 4 reed blocks required
52 notes & 3 voices = 4.5 reed blocks required
52 notes & 4 voices = 6 reed blocks required

What is particularly interesting to me is when we compare the following:

46 note CBA with 4 voices LMMH (4 reed blocks) = 184 reed (E to C#)

52 note CBA with 3 voices LMM (4.5 reed blocks) = 156 reed (E to G)

The instrument with less 'notes' on the keyboard (46) has more reeds overall, but requires less reed blocks to house them and also has a greater tonal range when we factor in the H voice as a range extender compared to a 3 voice LMM instrument. Even when we consider a 3 voice instrument with LMH, as the highest pitch accordion reed is generally C#8, therefore the benefit of 52 notes is lost on the H voice as it will be cut 6 notes early (at C#8 instead of G8).

Out of interest, is there any noticeable tonal quality difference in having 52 notes (x3 voices) distributed over 9 reed block sides rather than 46 notes (x4 voices) distributed over 8 reed block sides?

 

[Siegmund]

Can confirm that my 49x4 manages with 4 blocks, 25 reed plates to a side.

 

[debra]

Can confirm that my 49x4 manages with 4 blocks, 25 reed plates to a side.

Here is the "max": 28 reed plates to a side. These reed plates are all narrower than normal and the distance between the reed plates comes very close to zero. This 5 voice (Hohner Artiste X S) with 56 notes thus has 560 reeds on the treble side, on 280 reed plates.
(Plus another 232 reeds on 116 reed plates on the melody bass side).

 

[debra]

...

I believe my standard bass accordion with 4 voices (musette, no cassotto) has 4 blocks with 46 actual notes (and some fake buttons) - surely they can squeeze another 6 notes on each block? I imagine the construction would be much simpler to keep each voice to a particular reed block

See my picture in the earlier post: they already managed to put 28 notes on a single reed block side in Castelfidardo (Excelsior made this.) but you are now asking for 29... Don't be fooled by the apparent extra space still available, in that picture. It is needed for the register mechanism.

 

[Ventura]

i still mourn the loss of that amazing factory and period of time
Cemex/Excelsior
that photo shows a work of Art as well as Engineering and
precision manufacture to the level of excellence

 

[petch]

See my picture in the earlier post: they already managed to put 28 notes on a single reed block side in Castelfidardo (Excelsior made this.) but you are now asking for 29... Don't be fooled by the apparent extra space still available, in that picture. It is needed for the register mechanism.

you mean to say the inside of an accordion isn't like a tardis, with more space on the inside?

 

[debra]

you mean to say the inside of an accordion isn't like a tardis, with more space on the inside?

What I'm saying is that in the picture it may look like on the righthand side (the high notes) one could squeeze in another reed plate. But that position is where the "pass-through" from inside to outside for the register mechanism is. So you cannot add another note there.
Of course more notes would fit in a larger body, but this body is the same size as a Morino VI (or a Gola 459) and that's already very large.

 

[tcabot]

Bayans are 3x rows per voice I believe, even if they have cassotto. Western cassotto accordions are typically 2x per voice afaik. For cassotto, the cbas use the same boxes as PAs, but the keyboard is different (e.g. Super VI vs Chromo VI; Piano V vs Chromoton V, etc).
I've got the ultra-narrow plates too - if one was to believe the soviet ideas that a solid reed plate sounds better due to better frame weight & rigidity, one would expect the ultra-narrow reed plates to sound inferior, but that's most certainly not the case.
Excelsior does have a mindblowing bassoon in cassotto, and I wonder if the ultra-narrow plates contribute to that sound.

PS Apologies, just found out that you are talking about converter but no cassotto.
Converter often takes up a lot of space, requiring a bigger box, so it might be possible to fit 2x per voice into the RHS, but typically, non-cassotto CBAs have 3x per voice.
PPS Large CBA size is 19x18x19, so space for 3 extra notes.
PPPS are you thinking of switching from PA to CBA? CBAs are more fun - you can get mother of pearl buttons

 

[Walker]

​

PPPS are you thinking of switching from PA to CBA? CBAs are more fun - you can get mother of pearl buttons ​

I'll give you that... CBA's can have real mother of pearl buttons!

So thanks everyone for all the input into the 87 button accordion questions (did I ask 87 questions?)

I am indeed a piano accordion player. I play traditional music for occasional gigs. However, my greatest musical enjoyment comes from writing music and exploring the free bass instrument. I really like the Piano accordion with Quint converter system. I am inspired by the Italian players.

I have recently undertaken to write a book of 'miniatures' for free bass accordion learners (I have just finished my 6th piece for the book today) but know that many (most) free bass accordionists on these isles (and other places too) will play the CBA with chromatic free bass. I believe it is important to understand the 'character' of the CBA converter so that what I write feels 'natural' to play. I have borrowed a C system button accordion from our friend Ben Saunders in England. He is a terrific musician and was very kind to lend me an accordion. I intend to learn the C system button instrument in addition to the Piano accordion. It's no biggie. I have already made a start and I follow the classic Danish textbooks. Don't tell anyone, but I rather like the style of the Western European exponents of the CBA chromatic converter (not just Galliano on his CBA Quint).

So hopefully by getting 'hands on' with a CBA I can be more aware of the instrument, and not write awkward music (no multiple-octave bass jumps etc ).

At some point I will invest in a 87 button accordion... I like 87 buttons because I view the free bass accordion as a portable, miniature, free-reed organ. I value certain 'things' in any instrument; compactness, moderate dimensions, relatively light (around 12kg or less) and have a great tone.

The very largest accordions are not for me - if I want a work-out I'll go to the gym instead. I also like working within a 'parameter' of around 4 octaves on each side. This is where the 87 button comes in., hence the ridiculous questions about 3 & 4 voice variants...

I have a dream to place a good C system CBA instrument next to my Quint free bass PA. and I will write music all the live long day, with a fancy fountain pen, (apart from having to go to work) and play those accordions to my heart's content. I guess it's a hobby. ​

 

[losthobos]

I'll give you that... CBA's can have real mother of pearl buttons!

So thanks everyone for all the input into the 87 button accordion questions (did I ask 87 questions?)

I am indeed a piano accordion player. I play traditional music for occasional gigs. However, my greatest musical enjoyment comes from writing music and exploring the free bass instrument. I really like the Piano accordion with Quint converter system. I am inspired by the Italian players.

I have recently undertaken to write a book of 'miniatures' for free bass accordion learners (I have just finished my 6th piece for the book today) but know that many (most) free bass accordionists on these isles (and other places too) will play the CBA with chromatic free bass. I believe it is important to understand the 'character' of the CBA converter so that what I write feels 'natural' to play. I have borrowed a C system button accordion from our friend Ben Saunders in England. He is a terrific musician and was very kind to lend me an accordion. I intend to learn the C system button instrument in addition to the Piano accordion. It's no biggie. I have already made a start and I follow the classic Danish textbooks. Don't tell anyone, but I rather like the style of the Western European exponents of the CBA chromatic converter (not just Galliano on his CBA Quint).

So hopefully by getting 'hands on' with a CBA I can be more aware of the instrument, and not write awkward music (no multiple-octave bass jumps etc ).

At some point I will invest in a 87 button accordion... I like 87 buttons because I view the free bass accordion as a portable, miniature, free-reed organ. I value certain 'things' in any instrument; compactness, moderate dimensions, relatively light (around 12kg or less) and have a great tone.

The very largest accordions are not for me - if I want a work-out I'll go to the gym instead. I also like working within a 'parameter' of around 4 octaves on each side. This is where the 87 button comes in., hence the ridiculous questions about 3 & 4 voice variants...

I have a dream to place a good C system CBA instrument next to my Quint free bass PA. and I will write music all the live long day, with a fancy fountain pen, (apart from having to go to work) and play those accordions to my heart's content. I guess it's a hobby. ​

Congratulations..you've just levelled up to HERO status ...

 

[tcabot]

I value certain 'things' in any instrument; compactness, moderate dimensions, relatively light (around 12kg or less) and have a great tone.

Here's a concept from Soviet past. ~3 octaves in the left, ~3 octaves free bass in the right. I believe it had a catchy name of "Semi-Bayan".
If this was a high quality box with good reeds (2 voices in unison) and 5-row keyboards, I think it would be a winner. Perhaps, only 1 voice in the left hand side, but stick it in cassotto. Perhaps, Moschino in the left hand side (I'm still working towards this one).
I agree on the big boxes - they are way too bulky & heavy, and I don't have any bats in my family, so really don't need the ultrasound octaves. The lowest free bass octave sounds OK, but I can't see it being used very often, so that can be left out too. I think the accordion reed performs well in the middle. If you have C2-C5 in the LHS and C3-C6 in the RHS, that gives you a huge range - way more than most other musical instruments.

...Yep, I've started drafting a design of my dream acoustic accordion...
...I even tried making some reeds by hand with reasonable success (at this point, purely for educational purposes)...
But the build won't be happening any time soon, if ever.

 

[Walker]

Here's a concept from Soviet past. ~3 octaves in the left, ~3 octaves free bass in the right. I believe it had a catchy name of "Semi-Bayan".
If this was a high quality box with good reeds (2 voices in unison) and 5-row keyboards, I think it would be a winner. Perhaps, only 1 voice in the left hand side, but stick it in cassotto. Perhaps, Moschino in the left hand side (I'm still working towards this one).
I agree on the big boxes - they are way too bulky & heavy, and I don't have any bats in my family, so really don't need the ultrasound octaves. The lowest free bass octave sounds OK, but I can't see it being used very often, so that can be left out too. I think the accordion reed performs well in the middle. If you have C2-C5 in the LHS and C3-C6 in the RHS, that gives you a huge range - way more than most other musical instruments.

...Yep, I've started drafting a design of my dream acoustic accordion...
...I even tried making some reeds by hand with reasonable success (at this point, purely for educational purposes)...
But the build won't be happening any time soon, if ever.

Thanks for sharing the design ideas tcabot. It is just incredible that you have the skills to design and build accordions and reeds. Mind blowing! From what I have seen and read, there is a lot to like about Moschino system and you are definitely the man to see these ideas through. I agree a moderate range of notes goes further than we realise...

 

[tcabot]

you have the skills

Just toying with the idea at the moment. Too many ideas, not enough time. Necessary skills can be acquired when needed

But I'm getting a very good understanding of what I would like from an accordion. In terms of tone, keyboards, specs.
Unfortunately for me, it is very far from what's readily available, e.g. I'd be happy with just free bass. I guess I can have a Stradella or French bass box as a backup if I ever need chord bass... I just find that chord bass suits some music very well and doesn't suit other styles at all. It also seems to rob the right hand side of a lot of its dynamics and sweetness once the multiple LHS reeds kick in. Yes, one should certainly work on the bellows control to minimise this effect, but I recon RHS never sounds quite the same once you engage the chords. If you notice the pros, when they want to really open up the tone of their accordions, they like to play with a band accompanying them and they don't really use their LHS at all. The RHS then truly shines. A free bass with 1 voice does not create the same negative effect on the RHS dynamics, as, I'm guessing, it just doesn't suck nearly as much air as chord bass.

Once I free myself from the need for chord bass, then there's no need to go for a converter, as it seems to really complicate the mechanics, make the box large & heavy and limit the free bass to 3 or 4 rows. The current top priority is to try the moschino. If I like it, I'll work towards a moschino box. If not, I guess I can still benefit from a 5-row free bass keyboard instead of 3 or 4 rows.
Don't get any ideas about my playing skills - I just want the easiest system that I'm actually capable of using. Talented folks can use 3 rows on a bassetti or MIII or achieve virtuoso performance on 4-row bayans. I'm not even close to being talented . Just give me the easiest thing that I can annoy the neighbours with.

Just for a laugh I've made a couple reeds, using Cagnoni a manos as an example. Learned quite a lot while doing it, and even got reeds that play in the end and are close to the [extremely poor] quality that was coming out of soviet factories, but my fitting and riveting skills would really need to improve by a lot before I consider putting my reeds into a box. This makes me think of the semi-bayan idea, that 37x2 in the right+37x1 in the left is only just over a 100 reed pairs... That's doable. Can I get the tone that I want - that's to be found out. But honestly, everything is in early concept mode right now - it won't be happening before 2025, if ever.

 

[Siegmund]

Here's a concept from Soviet past. ~3 octaves in the left, ~3 octaves free bass in the right. I believe it had a catchy name of "Semi-Bayan".

Tula still makes these. They advertise them as "baby button accordions for young students". Both a 3-row model (BN-56) with 30 notes in each hand, and a 5-row model (BN-46) with 46 notes in the right and 37 in the left.