The B flat clarinet is by far the most common type of clarinet and the unmodified word clarinet usually refers to this instrument. However, due to a tendency for writers and historians to imitate the terms used to denote instruments in other family groups, the term soprano is sometimes used to apply not only to the B flat clarinet but also to the clarinets in A and C, sounding respectively a semitone lower and a whole tone higher than the B flat instrument, and even the low G clarinet - rare in Western music but popular in the folk music of Turkey - sounding a whole tone lower than the A. While some writers reserve a separate category of sopranino clarinet for the E flat and D clarinets, these may be regarded as soprano clarinets as well. All have a written range from the E below middle C to about the C three octaves above middle C, with the sounding pitches determined by the particular instrument's transposition.