Instrument family
Instruments in which thin metal tongues vibrate freely through a slot, driven by breath or bellows.
A free reed is a thin metal tongue fixed at one end over a slot in a plate. When air flows past it, the tongue swings back and forth through the slot without striking its edges — hence “free”. Each reed is tuned to one pitch, which is why free-reed instruments contain many reeds rather than changing pitch by altering tube length.
The accordion and the harmonica show two very different ways of putting the same idea to work: one supplies air with hand-operated bellows and is controlled from keys or buttons, the other is driven directly by the player’s breath. The free-reed principle was known in East Asia long before it reached Europe in the eighteenth and nineteenth centuries, where it inspired a wave of new instruments.
The accordion is a portable free-reed instrument in which the player pumps a pleated bellows to push air across metal reeds, choosing notes with keys or buttons on two sides. A patent granted in Vienna in 1829 is usually cited as its starting point, though similar instruments were being built at about the same time. It spread through migration and trade into dance, song and concert traditions on nearly every continent.
The harmonica is a small free-reed instrument played by breathing in and out across a row of holes, each leading to a pair of metal reeds. It grew from a crowd of early nineteenth-century experiments in German-speaking Europe, then spread across the world as a cheap, pocket-sized instrument. Diatonic, chromatic and tremolo models serve blues, folk, country, jazz and concert repertoire.