A harmonica including at least a comb including a plurality of chambers, a first plate including a plurality of blow reeds, a second plate including a plurality of draw reeds, the harmonica wherein each chamber of the plurality of chambers includes at least one material projection, each material projection being configured to reduce the oscillatory space of a draw reed, and in that it includes at least one additional plate arranged above the first plate and including a plurality of additional material projections, each additional material projection of the plurality of additional material projections being configured to reduce the oscillatory space of a blow reed.