The topic was addresses under a general Concertinas in July 2012 in a post I started. Attached below is a response from Wim Wakker which gave the history.
The keyboard dimensions for concertinas are more or less standard. You cannot change the spacing of the buttons without affecting playability. The diameter of a concertina button is primarily determined by the space available in the action. Anglo concertinas have fewer keys per sq. inch than english and duet and because of that can have a relative simple action and larger buttons.
Button size and action material were determined by production cost/method, not ‘playing comfort’.
Low end vintage instruments had bone buttons and wire action levers. The standard wire was ca.2mm in diameter and needed a lever hole in the button of 3+mm (room for the bushing). The walls needed to be c. 2mm to provide the necessary strength around the hole. Because of this, anglo buttons on instruments with wire levers were c.7mm in diameter. This was possible because of the low button count per sq. inch. The end plates are not bushed in these instruments.
Low end english and duet models also came with bone buttons, but because of the limited space in the action, they only came with the standard button diameter (c. 4.8mm). This required the much more expensive brass sheet levers rather than the crude wire levers. They used the same buttons and action in the ‘next step up the quality ladder’ anglos.
Better quality instruments came with metal capped/wooden core buttons (Wheatstone) or solid metal buttons (lachenal, etc.), sometimes with a silver tip. Early instruments had ivory buttons.
Deluxe models could have glass, silver or gold plated buttons. The quality of these instruments was the same as their standard counterparts. The exclusive button material just added a considerable premium to the price….
Early instruments (english) had flat ivory buttons. They were flat because of the production method they used. These flat tops allowed players (e.g. Regondi) to develop advanced techniques such as changing fingers on a (pushed down) button, playing fifths with one finger, etc. These techniques also show up in the concert repertoire of the day.
Around the 1880s Wheatstone started with domed metal caps. These are much easier to produce than flat tops and keyboards are much easier to regulate.
Flat top keys have a larger surface and allow for more advanced playing techniques. To illustrate, try this: play a button with your index finger (index finger= 1, middle finger2, etc.) on your concertina. Replace your index finger (1) with your middle finger ( 2) while you keep the button pushed down. You can also try replacing finger 1 with 3, 1 -4 (pinky), 1-2-3-4-3-2-1, etc..
If your repertoire/playing skills don’t require flat tops, domed ones work just as well. The extra surface of flat tops can be nice on duets or englishes, but don’t expect them to improve your playing skills… If you play anglo, don’t worry about button shapes… Button shapes don’t have anything to do with ‘speed’. Keyboard responsiveness is determined by key travel, airflow and key pressure.
All our Wakker models are available with flat or domed keys.
A concertina action should never hurt your fingers…Key pressure on a concertina should be around 70-80 grams. The key pressure needs to be around 200-300 gr. Before it will hurt your fingers. The problem is that some players keep pushing the button. It is the same principle as writer’s cramp.
Try this: push a button just hard enough for it to go down. Hold it in the down position and reduce pressure as much as possible without letting the button come up. You’ll notice that you hardly need any force to keep the button down.
Concertina Connection Inc.