I'm a newbie with the concertina, and purchased a Stagi 20 button Anglo, and am learning how to make it work. My main problem is that the buttons on the right side keep sticking and have to have an assertive pop to make them come back out properly. I got this concertina at a very good price, and except for the sticking problem I really like it to learn on. Does anyone have a simple solution to this, or should I consider buying a better beginners model? Thanks, in advance.