Harmonica
Comb

The comb is the main body of the instrument, which, when assembled with the reed plates, forms air chambers for the reeds. The term "comb" may originate from the similarity between this part of a harmonica and a hair comb. Harmonica combs were traditionally made from wood, but now are also made from plastic (ABS) or metal (including titanium for high-end instruments). Some modern and experimental comb designs are complex in the way that they direct the air.

Dispute exists among players about whether comb material affects the tone of a harmonica. Those saying no argue that unlike the soundboard of a piano or the top piece of a violin or guitar, a harmonica's comb is neither large enough nor able to vibrate freely enough to substantially augment or change the sound. Among those saying yes are those who are convinced by their ears. Few dispute that comb surface smoothness and air tightness when mated with the reed plates can greatly affect tone and playability. The main advantage of a particular comb material over another one is its durability. In particular, a wooden comb can absorb moisture from the player's breath and contact with the tongue. This can cause the comb to expand slightly, making the instrument uncomfortable to play, and to then contract, potentially compromising air tightness. Various types of wood and treatments have been devised to reduce the degree of this problem.

An even more serious problem with wooden combs, especially in chromatic harmonicas (with their thin dividers between chambers), is that, as the combs expand and shrink over time, cracks can form in the combs, because the comb is held immobile by nails, resulting in disabling leakage. Serious players devote significant effort to restoring wood combs and sealing leaks. Some players used to soak wooden-combed harmonicas (diatonics, without wind-savers) in water to cause a slight expansion, which they intended to make the seal between the comb, reed plates, and covers more airtight. Modern wooden-combed harmonicas are less prone to swelling and contracting, but modern players still dip their harmonicas in water for the way it affects tone and ease of bending notes.
keywords:frequency, punctuation:no_comma