Folk and Ethnic Musical Instruments

Free reed instruments like the accordeon or the harmonica belong to the family of free aerophones, where the pitch is not determined by changing the length of a vibrating air column (like for example in flutes etc.) Instead, most free aerophones control their pitch by changing the thickness and the length of one or several reeds. In addtion, the reeds of free reed instruments vibrate freely without touching anything, as opposed to those of beating reed instruments which are designed to touch or beat against the rim of the opening over which they are fixed.

Free-reed instruments are subdivided into unframed reeds (like for example a blade of grass held between two thumbs, a technique known as bilu in traditional Chinese music) and framed reeds, where the reed is enclosed in some kind of casing or frame. The accordion, the concertina, the bandoneón, the harmonica, the melodica and the harmonium are all (framed) free reed instruments.

Free reed instruments may also employ pipes or tubes, as do traditional Asian mouth organs like the sheng from China, the khene from Laos and the sho from Japan. In these instruments, the pipe merely reinforces the sound while its length has no influence on the pitch, which is determined by the reed. An exception in this regard are the traditional Asian free reed pipes, such as the hulusi and the bawu from China or the ding tac ta from Vietnam, which feature a freely vibrating reed, often enclosed in a gourd, in combination with a bamboo pipe equipped with fingerholes that produce different pitches.