This is the 'standard' 46 button layout for a Hayden concertina: I am contemplating the layout for a midi Hayden and, while it is easy and tempting to just add a gazillion extra buttons, I am mindful of David Barnert's objections to a large button field ( and of my own ability to get lost even on a smaller button field.   My question is: are there just one or two buttons on each side that are really worth adding to the 46 button