Gemshorn
The gemshorn is an instrument of the ocarina family that was historically made from the horn of a chamois, goat, or other suitable animal. The gemshorn receives its name from the German language, in which Gemshorn means a "chamois horn". According to Etymologist Francesco Perono Cacciafoco, the form could have prehistoric origins and come from Proto-Germanic *gămĭtă-χŭrnă-n < Indo-European *gʱŏm-ĭdó-ḱrhₐ-nŏ-m (or *gʱŏm-ĭdó-ḱrhₐ-nŏ-m > Gämshorn, indicating a "'specific' wind instrument, crafted by using the horns of ungulated animals and different from a hunting horn or a signaling horn".

History
The gemshorn was used in the 15th century. Examples have been unearthed in Italy, in Hungary and in Germany, including one intact instrument made of clay which dates at least to 1450, as it was found buried beneath the foundation of a house built at that time. The early history of the instrument is not well-known, but the oldest known illustration of one in a reference work is in Musica Getutscht (1511), by Sebastian Virdung. A skeletal figure is seen holding one in a Danse Macabre illustration dated to 1485. There is also mention of this instrument in "The Complaynt of Scotlande" as "ane gatehorn"(goat horn). They were primarily a pastoral instrument and were not widely known after the mid-to-late 16th century. With resurgent interest in early music in the 19th and 20th centuries, they have received new attention. Horace Fitzpatrick developed a form of gemshorn which adopted the fingering method of recorders and produced them in consort families, which have proven very popular since the 1960s.

Construction
Modern gemshorns are often made of the horns of domesticated cattle, because they are readily available, and their use prevents endangering wild species.  The hollow horn has tone holes down the front, like a recorder or clarinet.  The pointed end of the horn is left intact, and serves as the bottom of the instrument.  A fipple plug, usually of wood, is fitted into the wide end of the instrument, with a recorder type voicing window on the front of the horn, for tone production.
On more advanced models, there is a "tuning ring". This is a metal band or ring, placed between the voicing window and the top tone hole. A hole is drilled through this ring and the horn beneath. When the ring is turned with the fingers the hole is partially blocked. This lowers the flute's keynote by up to about one major tone. Partial wax closure of the dorsal (rear) thumb hole will accomplish the same keynote tuning.
Some recent makers have used synthetic materials in place of the animal horn. Another alternative, offered by some makers, is wooden gemshorns.

Playing and sound
16th-century illustrations show an instrument which had only a few tone holes, and a very limited range. The intact clay gemshorn, mentioned above, which was found beneath a 15th-century house, had a chromatic range of one octave. Modern makers have often chosen to build them using the Baroque recorder fingering.

The sound of the gemshorn is like that of other flutes, but with an ocarina-like lack of harmonic overtones.

Organ stop
There is a gemshorn organ stop, modeled after this instrument.  Its pipes are conical, with the wind going in at the wide end, as in the actual gemshorn. In organ pipe classification it is a flute/string hybrid.

See also
Early music
Helmholtz resonance
Ocarina
Pan flute
Pifana, a Corsican gemshorn
Tonette

References
Further reading
Perono Cacciafoco, Francesco. 2022. The Puzzle of a Horn: An Etymology for the Word 'Gemshorn'. Annals of the University of Craiova: Series Philology, Linguistics / Analele Universității Din Craiova: Seria Ştiințe Filologice, Linguistică, 44, 1 / 2: 141–154, link; DOI.

External links
Musica Antiqua's Gemshorn Page Gemshorn history, photos, mp3s
Photograph of a gemshorn
Gemshorn Society Ratingen Sheet music for the gemshorn (in German) Archived 2022-01-31 at the Wayback Machine