Also:       hora      gai      kai      

Contextual Associations

The horagai is the only surviving lip-reed aerophone instrument of Japan (gallery #1 and detail #1). This end-blown conch shell natural trumpet is used in different contexts: as a ritual, signaling, and protective instrument for sects of esoteric Buddhism and Shugendo (mountain asceticism shamanism); by fishermen strictly for signaling; and as an off-stage musical resource to index battle scenes in present day Kabuki theatre (Johnson, p. 693). Breaking down ‘horagai’ to its components--‘ho’ means ‘Buddhist law’; ‘ra’ ‘large conch’; and ‘gai’ or ‘kai’, ‘shell’ (ibid.)--its association with Buddhism is clear. The horagai pictured and described here was most likely used by a yamabushi (Shugendo practitioner) in training while wandering in the forests of Japan in search of spiritual insight. 


The crown of a cleaned conch shell of the variety Charonia tritonis is removed and refined, producing an opening to the spiral-shaped cavity of the shell. A conical mouthpiece of lacquered wood (in the case of the instruments described here) or of metal is attached over the opening (detail #2). The mesh bag in which this shell would be carried has been lost, although a fragment of such mesh rope is wrapped around the base of its mouthpiece.

Player - Instrument Interface and Sound Production

In Buddhist and Shugendo contexts, the horagai player carries the conch in a mesh bag slung over his shoulder. To sound the instrument, he lifts the shell up, still in its mesh, with both hands so that the mouthpiece end is pressed against his lips (either centered or to one side or the other of the emboucher). With diaphram pressure, an airstream is forced through the emboucher and the lip buzzing thus produced sets the enclosed air cavity of the shell into a mode of vibration. Various unstandardized and for the most part graphic notation systems (called kaifu, ‘shell notation’) have developed amongst sects of esoteric Buddhism and Shugendo in which the fundamental pitch is called ‘otsu’ and overtones ‘kan’ (Fukui, p. 52). The shell in gallery #1 produces three pitches: an otsu of approximately E4; and kan of E5 and B5. These are the first three partials of the harmonic series for the fundamental E4. The tone quality of the kan (E5 and B5) are noticeably thinner than that of the otsu. An additional overtone can be obtained on larger horagai, which would produce a lower fundamental pitch than the instrument pictured here. Several horagai being played as part of an urban shrine ceremony in Ise, Japan, can be seen and heard on this video link (the instruments seem to be sounded at points of transition within the ceremony, such as at these timings: 0:06; 0:51; 1:38; 2:23; and 5:03).


The adaptation of conch shells to ritual and signaling instruments dates back at least to Neolithic times (GDMI Conch p. 676). This transformation occurred worldwide, most commonly, but not exclusively, in cultures located along ocean coastlines (see Montagu 2018 for a survey of the distribution of conch trumpets today). The horagai was probably introduced to Japan from China in the 8th or 9th centuries CE during a period when Chinese esoteric Buddhism (called Mikkyo in Japan) was being imported by returning Japanese practitioners, most importantly amongst them Kukai, the founder of the Japanese Shingon sect of esoteric Buddhism (Fukui p. 48). Its use in Buddhist worship is up to the present day found almost exclusively in a very few Shingon sect Buddhist temples. As the syncretic practice of Shugendo (‘way of asceticism,’ combining elements of Shintoism, Confucianism, Taoism, Buddhism, and esoteric Buddhism developed between the 8th to the late-12th century CE [ibid.]), the horagai became an indispensable signaling and protective tool used by Shugendo practitioners (yamabushi) while in religious training, and remains so to the present day (in 1986 there was estimated to be 5,855 sub-sects of the six original Shugendo sects with more than twelve million believers [ibid., p. 49]). It is less clear when the horagai began to be used as a signaling instrument by fishermen. In the course of its history in Japan, the horagai was also, for a time, used as a military signaling instrument, which explains why it came to be used to index battle scenes in the context of Kabuki theatre.

Bibliographic Citations

de Ferranti, Hugh. 2000. Japanese Musical Instruments. New York: Oxford University Press.

Fukui, Hajime. 1994. “The Hora (Conch Trumpet) of Japan,” Galpin Society Journal 47: 47-62.

Johnson, Henry. 2014. “Horagai [hora, kai].” GDMI v.2: 693.

Haags Gemeentemuseum, and Onno Mensink. 1979. Traditionele muziekinstrumenen van Japan. Den Haag Haags Gemeentemuseum: Buren, In samenwerking met F. Knuf.

Montagu, Jeremy. 2018. The Conch Horn: Shell Trumpets of the World from Prehistory to Today. Hataf Segol Publications. Jeremy Montagu website, accessed August 23, 2019: http://www.jeremymontagu.co.uk/conch.pdf

Schechter, Jon M., and Mervyn MacLean/Michael Cwach. 2014. “Conch horn [conch trumpet, shell trumpet].” GDMI v.1: 676-677.

Yamabushi Ceremony - Ise, Japan. World Turtle Productions, LLC. YouTube video published on Apr 24, 2009: https://www.youtube.com/watch?v=iArVJkI__us


Instrument Information


Continent: Asia

Region: East Asia

Nation: Japan

Formation: Japanese

Classification (Sachs-Von Hornbostel revised by MIMO)

423.111.2 aerophone--natural labrosone end-blown conch; with mouthpiece

Design and Playing Features

Category: aerophone

Air cavity design: tubular - conical with open distal end

Source and direction of airstream: player exhalation through mouth into air cavity; unidirectional

Energy transducer that activates sound: lip reed (player’s lips) placed over open end of tube

Means of modifying shape and dimensions of standing wave in air cavity: none

Overblowing utilization: overblowing at consecutive partials

Pitch production: multiple pitches - selecting partials of a single cavity’s fundamental through overblowing


11.5 in. length 4.5 width

Primary Materials

shell - conch

Entry Author

Roger Vetter