The Crooked Horn ( in ancient sources also Krumhorn or Krumphorn written; engl: Crumhorn; Italian:. Cromorna, Storto; French: Cromorne, Tournebout ) is a woodwind instrument with a double reed, cylindrical tube drilled and wind capsule. It has seven permanent front finger holes and one thumb hole for the left thumb. The range is a major ninth. In modern Krummhorn the range is extended by two flaps up and then is a eleventh. The overblowing was not originally intended, but it is possible in modern Krummhorn with the help of the flaps, the instrument because of the cylindrical hole in the twelfth overblows. Sound but very severe overblown tones differ from the other tones. Can be particular with the low instruments each lowest notes by a slight lowering of the usual blowing pressure also underblowing, with the same handle is heard instead of the usual tone whose lower fifth, with the intonation of these sounds is difficult. The instrument has virtually no dynamic range, Blasdruckänderungen lead to changes in pitch and therefore serve the intonation, which is especially used in fork handles.

There are tones of voice soprano, alto, tenor, bass and great bass. Smaller and larger instruments were tentatively built, but could not prevail. As with most woodwind instruments of the Renaissance, the c / f mood is common:

Alto and bass are occasionally also a whole tone higher, so with the lowest note g0 and G built. Crumhorns are chromatically with the exception of the small second playable by fork handles to the lowest tone.

The Krummhorn was developed in Europe in the 15th century and comes from a medieval instrument with a straight tube and an animal horn ( cow or goat) at the lower end from. In the 16th century the instrument was widespread. The musical transition from the Renaissance to the Baroque in the 17th century it became unfashionable. Since the mid-20th century crumhorns be re- built and played. In addition to playing music from the Middle Ages and Renaissance, the Krummhorn is occasionally used also in folk and modern music.

There is an identically similar sounding organ stops, usually about 16 ' or 8'. This Lingualregister has cylindrical cup with mostly natural length.