A quarter tone clarinet is an experimental clarinet designed to play music using quarter tone intervals.
Around 1900, Dr. Richard H. Stein, a Berlin musicologist made the first quarter-tone clarinet, which was soon abandoned.
Using special fingerings, quarter tones may be produced by a skilled player on a conventional clarinet. However, such fingerings are awkward in rapid passages, and results tend to vary from one clarinet to another. In the 1920s Alois Hába commissioned a quarter tone clarinet from the Kohlert company of Grazlitz. At some point,[vague] another German, the instrument builder Fritz Schüller (1883-1977) of Markneukirchen made an attempt to create a quarter tone clarinet to overcome these problems. It consisted of a single mouthpiece connected to two parallel bores, one slightly longer than the other; effectively these were two clarinets tuned a quarter tone apart. A single set of keywork controlled the tone holes of both bores simultaneously, and a valve was provided to switch rapidly from one bore to the other.