The Accordion and How it Works

By Paul Pasquali

The accordion belongs to the family of reed instruments much like the clarinet and the oboe. However, the reeds of an accordion are made of thin pieces of metal rather than wood. Besides belonging to the wind and reed instrument families, the accordion belongs to an even more exclusive family known as FREE REED instruments.

When a clarinet is played, its reed vibrates against the mouthpiece of the clarinet and its travel is restricted. Double-reeded instruments, like the oboe, have two reeds that vibrate against each other and their travel is restricted. The reeds of the accordion, when they vibrate, are FREE to travel in both directions with no restrictions. It is this FREE REED principle that inherently gives the accordion an extreme amount of expressive capability.

The accordion uses two sets of reeds for each tone produced. One reed is used when the bellows are pulled and another reed is used when the bellows are pushed. If a single reed were used for both draw and push, the pitch would vary slightly depending on the travel of air over the reed. For this reason, each reed is actually a set of two reeds that are attached to opposite sides of a single reed casing. A small strip of leather is attached to the front and back sides of the casing so that only one of the two reeds in the casing can sound (depending on the direction of the bellows). The reed casings are then attached to a wooden reed block using beeswax. This wooden reed block has a small cavity for each set of reeds (casing).

The number of reed blocks determines the range, sound and size of the instrument. These blocks are then attached to opposite sides of the accordion. The bass reed blocks are attached to the left hand section and the treble reed blocks are attached to the right hand section. The bellows which then link the two sides of the accordion are then attached.

The bellows produce the air (wind) necessary to cause the reeds to vibrate. The amount of pressure the player exerts on the bellows then determines the amount of sound the reeds produce. Mechanical valves are then operated by the player when he touches the keys and or buttons which open and close air passages to the desired reed(s).

A standard professional size accordion, with four sets of treble reed blocks and five sets of bass reed blocks, has a total of 448 individual sounding reeds. This same standard instrument, with 120 bass buttons and 41 treble keys, can contain over 4,000 individual parts.