There are mainly two sections to a harmonica holder. The first one out of them is that part that goes around the neck. This part will hug around the contour of the neck and rests on the collarbone. Even though it won’t be tight around the neck, it should sit snugly so that it won’t move around unintentionally. The other part is the part that holds the harmonica. This consists of simple parallel plates with adjustable screws at either end. Tighten the screws so that the instrument won’t fall out while playing. But also, be careful not to tighten them too much to avoid damaging the instrument.