That is what I figured if you wanted to play all types tunes. I also thought it might be easier to learn on but not sure about that. It may not matter. I am sure there are a lot of tunes a person could learn on with the 20 button one would have to realize if it was in a key needing sharps and flats and their concertina was a G/C instrument they may want to avoid the tune or transpose it to G,C, Am,or Em.