The traditional accordion of choice where I live is the melodeon, a diatonic button accordion which I believe is unisonoric too. I'm not sure because I've never actually played one.
I've just learnt that there's going to be a melodeon making course in March. I was quite tempted by this as I would love to know more the insides of accordions. Unfortunately I don't really have the skills. One day maybe...
Link: Melodeon Marking Course
Recent Comments