The pump organ or reed organ is a type of musical instrument that creates sound using free reeds. These reeds are thin metal strips that vibrate when air moves over them inside a frame. Different types include the pressure-based harmonium, the suction reed organ (which uses a vacuum system), and the Indian harmonium. Earlier versions of these instruments include the physharmonica and the seraphine.

Historical examples of reed organs include the Kunstharmonium and the American reed organ. These instruments were smaller and easier to move than pipe organs, so they became common in small churches and homes during the 19th century. However, they had limited loudness and a narrow range of sounds. Most had one or two keyboards, and foot pedals were rarely included. More expensive models had a wider variety of tones, and those used in churches or wealthy homes were often placed in beautifully made wooden cases.

Between the 1850s and 1920s, millions of reed organs and melodeons were made in the United States and Canada, with some sold in other countries. Important makers of these instruments included the Cable Piano Company, Estey Organ, and Mason & Hamlin.

In addition to large, furniture-sized instruments used in Western countries, smaller versions were also created. The portable, hand-pumped Indian harmonium, which was based on Western designs like the guide-chant in the 19th century, became an important instrument across the Indian subcontinent. Today, the Indian harmonium is widely used by Sikhs, Hindus, and Muslims for devotional music such as qawwali, ghazal, kirtan, and bhajan. It is also used in Indian classical music and in Western yoga and kirtan communities.

History

During the first half of the 18th century, a free-reed mouth organ called a sheng was brought to Russia. The instrument gained attention because of Johann Wilde’s use of it. At that time, the free-reed mechanism was unknown in Europe, and the idea quickly spread from Russia to other parts of the world.

Christian Gottlieb Kratzenstein (1723–1795), a professor of physiology at the University of Copenhagen, is credited with creating the first free-reed instrument in the Western world. He won an annual prize in 1780 from the Imperial Academy of St. Petersburg for this work.

The first free-reed organ was built by Abbé Georg Joseph Vogler in Darmstadt after Kratzenstein’s concept. The design of the harmonium, which uses free reeds, was based on the earlier regal. In 1810, Gabriel-Joseph Grenié (1756–1837) displayed a harmonium-like instrument he called the orgue expressif ("expressive organ") because it could produce more dynamic changes, such as crescendos and diminuendos.

Alexandre Debain improved Grenié’s design and patented his version under the name "harmonium" in 1840. Around the same time, Jacob Alexandre and his son Édouard introduced the orgue mélodium in 1844. Hector Berlioz wrote about the instrument in his book Grand traité d'instrumentation et d'orchestration modernes, published in Paris around 1843 or 1844. He also mentioned the instrument in later writings and included it in L'enfance du Christ, Part 1, Scene vi, where it was played off-stage. Franz Liszt performed the part during a concert conducted by Berlioz in Weimar on 21 February 1855.

A mechanic who had worked at Alexandre’s factory moved to the United States and invented the suction bellows, replacing the outward-blowing bellows used in earlier models. After 1885, the Boston-based firm Mason & Hamlin adopted the suction bellows, which became the standard in America.

The term "melodeon" became linked to concert saloons in Victorian-era America, named after the reed instrument. Over time, the word was used to describe entertainment venues for men.

Harmoniums were most popular in the West during the late 19th and early 20th centuries. They were especially used in small churches and chapels where pipe organs were not practical. In Adventures of Huckleberry Finn, Chapter XXVII, a "melodeum" (likely a mix of "melodeon" and "harmonium") is mentioned in a scene about a funeral.

Harmoniums were lighter and more durable than similar-sized pianos, making them ideal for export to colonies with poor transport systems. Unlike pianos, they stayed in tune even in hot or humid climates. Special models treated with chemicals to protect against woodworm and pests were made for export.

At their peak around 1900, harmoniums ranged from simple models with few features to elaborate ones with ornate cases, multiple stops, and fake pipe displays. Some had two manuals or pedalboards, though these larger models needed an assistant or electric blowers to operate. Compact, folding reed organs were also made for missionaries and traveling evangelists.

The invention of the electronic organ in the 1930s began the decline of the harmonium in the West. Its popularity as a home instrument had already decreased in the 1920s. The Hammond organ offered better sound, easier maintenance, and a smaller size, making it a better choice. Harmoniums also became more complex due to many different patent designs.

The Estey company was the last major North American manufacturer, stopping production in the mid-1950s. A few Italian companies continued making harmoniums until the 1970s. As harmoniums aged and parts became hard to find, many were discarded or modified, often with electric blowers added in ways that damaged their original design.

Today, most Western-style harmoniums are kept by collectors, while the Indian harmonium remains widely used in South Asia.

Modern electronic keyboards can copy the sound of traditional pump organs.

The foot pump organ (足踏みオルガン, ashibumi organ) was introduced to Japan during the early Meiji period by foreign Christian missionaries. Used in churches and schools, the reed organ became a key tool for music education, introducing many Japanese people to Western instruments.

The first reed organs made in Japan were produced by the Nishikawa Organ Company in Yokohama. Later, Torakusu Yamaha, who started as a medical equipment repairman, began making reed organs in Hamamatsu after fixing an imported American model. These efforts helped make Hamamatsu a major center for musical instrument production in Japan.

From the late 19th to early 20th centuries, reed organs were installed in schools nationwide and became central to public singing education. Their affordability, durability, and ease of maintenance made them popular. By the early Shōwa period, reed organs were common in most Japanese elementary schools, helping spread Western music literacy.

Domestically made reed organs ranged from simple models with 39 or 49 keys to larger ones with multiple stops, swells, and pedalboards, mainly for teacher training colleges and music schools.

After the mid-20th century, reed organs declined in popularity with the rise of pianos and electronic instruments. However, they are still remembered fondly by those who grew up with them. Museums like the Hamamatsu Museum of Musical Instruments preserve and display historical reed organs, highlighting their role in Japan’s modernization and music education.

In several Asian countries, especially former Japanese colonies like Taiwan and South Korea, treadle-operated reed organs became common due to Japanese influence.

In China, the reed organ was introduced

Acoustics

The sounds made by these instruments come from a part called the free-reed mechanism. This mechanism works the same way in Western and Indian harmoniums, as well as in reed organs. In 1875, Hermann von Helmholtz wrote a famous book called On the Sensations of Tone. He used the harmonium to study different ways of tuning musical notes.

Helmholtz used two keyboards and two sets of pipes tuned differently to compare Pythagorean, just, and equal temperament tunings at the same time. He divided the octave into 28 tones, which allowed playing in 12 minor and 17 major keys using just intonation without the unpleasant sounds that usually happen with standard octave divisions. However, this system was hard to use. Other instruments were made for experiments, including Bosanquet’s Generalised keyboard (1873), which had 84 keys for a 53-tone scale. Another experimental reed organ was built by Poole.

Lord Rayleigh used the harmonium to measure frequencies indirectly. He used approximate equal temperament intervals and their overtones to count beats. The harmonium’s clear overtones helped two listeners count beats accurately, but Rayleigh noted that keeping the bellows pressure steady was difficult and could change the pitch.

Reed organs work like accordions or concertinas but are usually placed on the floor in a wooden case. They use either pressure or suction bellows. Pressure bellows let players control the volume better by changing how fast they press the pedals. In North America and Britain, pressure-bellows organs are called harmoniums. In continental Europe, any reed organ is generally called a harmonium, no matter the bellows type. Pressure-bellows instruments were harder and more expensive to make, so most North American and British reed organs and melodeons used suction bellows instead.

The sound produced by reed organs depends on the blowing pressure. The main note’s frequency slightly decreases with medium pressure compared to low pressure but increases again at high pressure, especially for low notes. Measurements show the reed moves in a wave-like pattern with sharp changes when it bends.

The main note’s frequency is close to the reed’s natural vibrating frequency. The extra sounds made are mostly harmonics, but a weak inharmonic sound at about 6.27 times the main frequency has been observed.

Besides the main vibrating movement, weaker side-to-side and twisting movements have been measured. Twisting movements happen because of small differences in the reed’s shape. During the start of a note, the main vibration and a secondary side-to-side or twisting movement are mostly active.

So far, how sound spreads from the reed to the instrument’s body and how they interact has not been studied much.

The special way reeds vibrate in free-reed instruments affects how the harmonium performs. The reed, attached to a metal frame, moves in a self-sustaining way as air flows through the bellows and reservoir. This system is nonlinear, meaning it doesn’t behave in a simple way. The reed’s movement is limited by forces that slow it down, keeping the sound pressure stable. A certain minimum pressure is needed to make the reed vibrate. Between these pressure levels, the reed’s movement grows and fades rapidly.

Repertory

The harmonium was considered by Curt Sachs to be an important instrument for music of the Romanticism period (1750s–1900). He described it as an instrument that "balanced between two ways of expressing music" and "needed the strong power and clear sounds of wind instruments."

Compositions for the harmonium were created by European and American classical composers. It was also used in folk music traditions in the Appalachian and Southern regions of the United States.

The harmonium played an important role in the revival of Nordic folk music, especially in Finland. In the late 1970s, most schools where music bands met had a harmonium. It became common for bands to include a harmonium in their performances. A typical folk band in Western Finland often included a violin, double bass, and harmonium. A practical issue limited the use of both the harmonium and accordion in the same band: harmoniums were tuned to 438 Hz, while accordions were tuned to 442 Hz. Key players in the revival of Nordic folk music using the harmonium included Timo Alakotila and Milla Viljamaa.

In the Netherlands, the introduction of the harmonium led to a rise in religious music performed at home. Its sound, similar to an organ, allowed Reformed families to sing hymns and psalms together. Many hymns were written specifically for voice and harmonium, including those by Johannes de Heer.

The harmonium repertoire includes pieces originally written for church organs. These pieces can often be played on a harmonium because they require a limited range and fewer stops. For example, Bach’s Fantasia in C major for organ (BWV 570) is suitable for a four-octave harmonium.

Other examples of works featuring the harmonium include:

• Alban Berg. Altenberg Lieder
• William Bergsma. Dances from a New England Album, 1856 for orchestra, which includes parts for melodeon (movements I–III) and harmonium (movement IV).
• William Bolcom. Songs of Innocence and of Experience for orchestra, choirs, and soloists, which includes parts for melodeon, harmonica, and harmonium.
• Anton Bruckner. Symphony No. 7, an arrangement for chamber ensemble prepared in 1921 by students and associates of Arnold Schoenberg. It was scored for two violins, viola, cello, bass, clarinet, horn, piano (4-hands), and harmonium. The arrangement was never performed before it was abandoned.
• Frederic Clay. Ages Ago, an early work with a harmonium part (libretto by W. S. Gilbert).
• Claude Debussy. Prélude à l'après-midi d'un faune, a chamber ensemble arrangement by Arnold Schoenberg.
• Antonín Dvořák. Five Bagatelles for two violins, cello, and harmonium, Op. 47 (B.79).
• Edward Elgar. Sospiri, Adagio for String Orchestra, Op. 70 (scored for harp or piano and harmonium or organ). Vesper Preludes.
• César Franck. L'Organiste (1889–1890), a collection of pieces originally written for harmonium, with some pieces including piano accompaniment.
• Alexandre Guilmant. Author of many duos for piano and harmonium, including: Symphonie tirée de la Symphonie-Cantate "Ariane" (Op. 53), Pastorale A-Dur (Op. 26), Finale alla Schumann sur un noël languedocien (Op. 83).
• Paul Hindemith. Hin und zurück (There and Back), an operatic sketch that uses a harmonium for stage music.
• Sigfrid Karg-Elert. Various works for solo harmonium.
• Kronos Quartet. Early Music, an album featuring several pieces with harmonium.
• Henri Letocart (1866–1945). 25 pieces for harmonium, Premier cahier.
• Franz Liszt. Symphonie zu Dantes Divina Commedia, Movement II: Purgatorio.
• Gustav Mahler. Symphony No. 8.
• George Frederick McKay. Sonata for Clarinet and Harmonium (1929), which can also be adapted for piano or violin.
• Martijn Padding. First Harmonium Concerto (2008) for harmonium and ensemble.
• Elise Rondonneau (active 1827–1860s). Composed many works specifically for harmonium.
• Gioachino Rossini. Petite messe solennelle, scored for twelve voices, two pianos, and harmonium.
• Camille Saint-Saëns. The Barcarolle, Op. 108, scored for piano, harmonium, violin, and cello.
• Arnold Schoenberg. Herzgewächse, Op. 20, for high soprano, celesta, harp, and harmonium. Weihnachtsmusik, for two violins, cello, harmonium, and piano.
• Franz Schreker. Chamber Symphony Vom ewigen Leben.
• Richard Strauss. Ariadne auf Naxos, an opera (libretto by Hugo von Hofmannsthal) that uses a harmonium in its orchestration. It requires an instrument with many stops, as specified in the score.
• Pyotr Ilyich Tchaikovsky. Manfred Symphony, fourth movement.
• Louis Vierne. 24 Pièces en style libre pour orgue ou harmonium, Op. 31 (1913).
• Anton Webern. Five Pieces for Orchestra, Op. 10.
• Alexander Zemlinsky. Six Maeterlinck Songs / Lyric Symphony.

Artists

• Ivor Cutler, a Scottish comedian and musician
• Krishna Das, an American kirtan singer, composer, and recording artist
• Farrukh Fateh Ali Khan, a Pakistani qawali performer, composer, and recording artist
• Mariana Sadovska, a Ukrainian singer, composer, and recording artist
• Radie Peat, a singer and musician from the band Lankum
• Nico, a German singer, songwriter, actress, model, and recording artist

Western popular music

Harmoniums have been used in Western popular music since at least the 1960s. John Lennon played a Mannborg harmonium on the Beatles' hit single "We Can Work It Out," released in December 1965. The band used the instrument in other songs recorded during the sessions for their Rubber Soul album. They also used the harmonium on the famous "final chord" of "A Day in the Life" and on the song "Being for the Benefit of Mr. Kite!," both from the 1967 album Sgt. Pepper's Lonely Hearts Club Band. The group's hit single "Hello, Goodbye" and the track "Your Mother Should Know" were both written using a harmonium.

Many other artists later used the instrument in their music. Pink Floyd included the harmonium on the title song "Chapter 24" from their first album The Piper at the Gates of Dawn in 1967. Elton John used the harmonium on his 1973 album Don't Shoot Me I'm Only the Piano Player, 1976's Blue Moves, the 1978 album A Single Man, and 1995's Made in England. German singer Nico used the harmonium as her main instrument during the late 1960s and 1970s on albums such as The Marble Index, Desertshore, and The End….

Donovan used the harmonium on his 1968 album The Hurdy Gurdy Man, where he played it in background music with a repetitive sound on the song "Peregrine." John Cameron also played the harmonium on his song "Poor Cow" from the same album. Robert Fripp of King Crimson played a pedal harmonium borrowed from lyricist Peter Sinfield on the title track of the band's 1971 album Islands.

More recently, Roger Hodgson from Supertramp used his harmonium on many of the group's songs, including "Two of Us" from Crisis? What Crisis?, "Fool's Overture" from Even in the Quietest Moments…, the title track to their 1979 album Breakfast in America, and "Lord Is It Mine." Hodgson also used a harmonium on "The Garden" from his 2000 solo album Open the Door. Greg Weeks and Tori Amos have both used the instrument in their recordings and live performances.

The Damned singer Dave Vanian bought a harmonium for £49 and used it to compose "Curtain Call," the 17-minute closing track from their 1980 double LP The Black Album. In 1990, Depeche Mode used a harmonium on a version of their song "Enjoy the Silence." The Divine Comedy used a harmonium on "Neptune's Daughter" from their 1994 album Promenade. Sara Bareilles used the harmonium on her 2012 song "Once Upon Another Time." The closing track to Radiohead's 2000 album Kid A, titled Motion Picture Soundtrack, makes heavy use of a harmonium pedal organ, which contrasts with many other tracks on the album that are almost entirely electronic.

During the 1990s, Hindu and Sikh-based devotional music known as kirtan, which originated in India during the 7th–8th century, became popular in the West. The harmonium is often played as the lead instrument by kirtan artists, including Jai Uttal, who was nominated for a Grammy award for new-age music in 2004, Snatam Kaur, and Krishna Das, who was nominated for a Grammy award for new-age music in 2012.

Types

From the perspective of protecting cultural items and their repair and upkeep, pump organs are often divided into different types.

Historically, the earliest pump organs were similar to pipe organs, such as the positive and portative types, which used bellows to power resonance pipes (these are also called pumped pipe organs).

In the 17th century, small reed-pipe organs known as regals began to change. Their reed pipes were replaced with beating reeds, and their design became more like the rocking melodeon, early small pump organs, or early accordions.

By the early 19th century, free reeds could be mass-produced in factories. This led to the invention of various free reed instruments, including early pump organs (around 1810), accordions (around 1822/1829), and the Symphonium (around 1829), which is considered an early harmonica.

• Positive organ (a small pipe organ with bellows)
• Portative organ (a portable pipe organ with bellows)
• Regal without pipes (circa 1600) (a beating reed organ without pipes after the 17th century)
• Accordion (circa 1830) (invented around 1822/1829)
• Symphonium [de] (circa 1830) (invented around 1829)

Note: The term "melodium" can be used interchangeably with "melodion" and "melodeon."

• Orgue-expressif [fr] (invented in 1810 by Gabriel-Joseph Grenié [fr], Paris) or Mélodium
• Portable or folding: Physharmonica (invented in 1818 by Anton Haeckl, Vienna)
• Seraphine (invented in 1833 by John Green, London)
• Portable or folding: Harmoniflûte [fr] (introduced in 1855)

Harmoniums are free-reed organs that use a pressure system.

• Flattop harmonium (circa 1865) by Alexandre Debain, a French inventor of the harmonium (patented in 1842)
• Kunstharmonium [de] (French: harmoniums d'art) with Celesta, by Auguste Victor Mustel [fr], Paris (1890)
• Piano-mélodium [fr] and Orgue-mélodium (invented in the mid-19th century by Alexandre Père et Fils [fr])
• Guide-chant
• Indian harmonium, which remains influential in Indian music
• Chapel harmonium
• Two manual with pedal harmonium by Theodor Mannborg [de] (1911)
• Enharmonic harmonium: Orthotonophonium (1870s/1914)
• Player harmonium (1888–1903, disc-type)

Suction reed organs are free-reed organs that use a vacuum system.

Note: The term "melodeon" can be used interchangeably with "melodion" and "melodium." For the "melodeon" as a type of accordion, see Diatonic button accordion § Nomenclature.

• Rocking melodeon or lap organ (1825)
• Seraphine of the United States (circa 1835 by James A. Bazin, MA)
• Portable melodeon or lyre-leg melodeon
• Piano-style melodeon (circa 1867)

• Folding reed organ (19th century)
• Flattop reed organ: melodeon or American reed organ
• Parlor organ: melodeon or American reed organ by American Reed Organ Co., Rotterdam
• Chapel organ
• Piano case reed organ
• Two manual with pedal reed organ (pipe-top)
• Enharmonic reed organ (1868/1871) by Joseph Alley
• Mechanical free-reed instrument, Organette (1878)

• Electric-blower driven reed organ
• Electric-blower driven reed chord organ (1960s)
• Electrostatic-pickup reed organ (1930s–1960s)
• Electronic organ (1939–)