A melodeon or diatonic button accordion is a type of musical instrument that produces sound when air passes through reeds. It is a kind of button accordion with a melody-side keyboard that has one or more rows of buttons. Each row plays the notes of a single diatonic scale. The bass-side keyboard has buttons most often grouped in pairs. One button in each pair plays the main note of a chord, and the other plays the matching major triad (or, sometimes, minor triad).

Diatonic button accordions are widely used in many countries. They are mainly played for popular music, traditional folk music, and modern versions of these styles.

History

The accordion, like many modern instruments, was created by combining different ideas at the start of the 19th century. However, its earliest ancestors, which used free reeds, were made as far back as 3000 BC in China and Laos. Instruments like the sheng and the khene are still used today in those regions. European travelers who visited Asia brought back descriptions and drawings of these instruments, which appeared in books and illustrations between the 1600s and 1700s. Combining the free reed idea with new technologies for making and copying instruments during the late 1700s and early 1800s led to many new inventions. Some of these instruments, like the harmonium, concertina, and harmonica, are still used today. Others, such as the harmoniflute, flutina, and aeoline, are rarely seen and only found in museums.

Cyrill Demian, an Austrian man with Armenian heritage, is usually credited with inventing the accordion because he filed a patent for it on May 6, 1829. The accordion gets its name from the way it works: pressing a button or key can produce a chord, which is a group of notes played together in harmony. It was designed to help singers by providing simple harmony, but its basic design—using bellows operated by the musician to make chords with one touch—allowed it to be used in many ways.

After Demian’s invention, other inventors and instrument makers quickly copied and changed the accordion. While Demian’s version only played chords, others redesigned the right-hand keyboard so each key played a single note. By the middle of the 19th century, left-hand buttons for making chords were also added. In 1840, Louis Douce patented the unisonoric or double-action accordion. In 1850, Franz Walther made the first chromatic button accordion. It was not until the late 1800s that Paolo Soprani began making bisonoric accordions in large numbers. These are the ancestors of today’s piano (keyboard) accordions, which are chromatic rather than diatonic. Around the start of the 20th century, accordions with three rows of buttons, both chromatic and diatonic, appeared. At this time, German companies like Hohner began to influence the design of the accordion keyboard, creating a standard layout: two rows of diatonic buttons separated by a small space.

Nomenclature

The diatonic button accordion is known by different names in various English-speaking regions.

• In Britain and Australia, the instrument is often called a melodeon (Scottish Gaelic: meileòidean or am bogsa), no matter if it has one, two, or three rows of melody buttons.
• In Ireland, melodeon (Irish: mileoidean or an bosca) refers only to instruments with one row of melody buttons. Instruments with two or three rows are called button accordions or simply accordions.
• In North America, both one-row and multi-row instruments are usually called accordions. Historically, melodeon was also used for certain 19th-century free-reed organs. In African American folk traditions, the one-row instrument is sometimes called a windjammer, especially in zydeco and Cajun music.

To avoid confusion, the term diatonic button accordion (or DBA) will be used in the rest of this article.

Other regions use different names:
– Basque: trikiti, trikitixa, soinu txikia, or akordeoi diatonikoa.
– Brazilian Portuguese: oito baixos (eight basses), sanfona de oito baixos, pé de bode (goat foot), acordeão diatônico, or gaita-ponto.
– Catalan: acordió diatònic.
– Dutch: trekharmonika or trekzak.
– Estonian: lõõtspill.
– Finnish: kaksirivinen haitari.
– France: accordéon diatonique (commonly called diato); mélodéon sometimes refers to one-row instruments.
– German: Ziehharmonika, Handharmonika, or Knopfakkordeon.
– Switzerland: Schwyzerörgeli (a type with a double-action bass keyboard).
– Austria: Steiirische Harmonika (a type with amplified bass notes).
– Italy: fisarmonica diatonica or organetto.
– Limburgish: trèkzak or kwetsjbuul/kwetsjbujel.
– Lithuanian: Armonika.
– Mexico and Colombia: acordeón diatónico or acordeón de botones.
– Norway: Torader (two-row) or Durspill (major instrument, covering all row numbers).
– Portugal: concertina (not to be confused with the English word concertina).
– Russia: garmon.
– Czech and Slovak: heligonka or heligónka.
– Slovenian: diatonična harmonika or frajtonar'ca.
– Sweden: Durspel.
– Argentina: verdulera.

Definitions:
– DBA: Short for diatonic button accordion.
– Single-action: An instrument where each key or button produces two notes, similar to bisonoric (a term based on French bi-sonore and German wechseltönig).
– Double-action: An instrument where each key or button produces one note, similar to unisonoric (a term paired with bisonoric).
– Reversal: On a single-action instrument, a button or key that plays a note found elsewhere on the keyboard but requires blowing or pulling the bellows in the opposite direction.
– Accidental: A note from the chromatic scale that is not part of the diatonic scale of a DBA's "home" key.

Action

Most diatonic button accordions have a "single-action" (or bisonoric) keyboard. This means each button plays two different notes: one when the bellows are pushed (closed) and another when the bellows are pulled (opened). These instruments work in a way similar to a harmonica.

In contrast, other types of accordions, such as piano accordions and chromatic button accordions, are "double-action" (or unisonoric). This means each key plays only one note, no matter if the bellows are pushed or pulled.

Other single-action or bisonoric instruments in the free-reed family include the German concertina, the Anglo-German (or "Anglo") concertina, the bandoneon, the Chemnitzer concertina (see concertina), and the mouth organ (harmonica).

Some diatonic button accordions, such as the garmon, are double-action.

Distribution of notes on the keyboard and range

Each button on a melody row plays two notes, so four buttons can cover all the notes in a diatonic scale.

For example, on a melody row tuned to the key of C, the lowest octave of the instrument’s range is divided among four buttons as follows:

Note: The first button in this example, labeled 1, is often the third or fourth button in a row on the instrument. Also, the pattern of pushing and pulling to move up the scale changes when returning to the root note. This ensures the root note in both octaves (C and C’ in this example) are played using the same push direction. This also helps keep melody notes aligned with the ideal direction for left-hand chords.

When the bellows are pressed, every button plays a note from the major triad of the home key. In this case, the pattern CEG repeats across the keyboard. The other notes in the diatonic scale are played when the bellows are pulled outward.

Since there are seven notes in the diatonic scale and each button plays two notes, the pairing of notes on buttons changes in each octave. In the second octave, for example, E is paired with D (instead of F, as in the first octave), and this pattern continues.

Each row usually covers two full octaves, with a few extra notes above and below. This makes the changing note pairings between octaves easier to manage.

For detailed diagrams of typical note layouts on diatonic button accordions, visit melodeon.net.

Available keys

A one-row instrument can play music in a single major key and its related minor key. For example, an instrument in D can play music in D major and B minor. However, the range of music that can be played on a one-row instrument is broader than this example shows. In addition to D major and B minor, the instrument in D can also play music in A Mixolydian and E Dorian scales. It can also play music using scales that skip some notes, such as pentatonic scales that start on D, G, or A.

Multi-row systems

A one-row DBA is light and compact. However, it can only play the notes of a single diatonic scale. Since the mid-to-late 19th century, instruments with more than one row have been made to give players more choices for scales and tonalities.

Multi-row systems are divided into two main types: "fourth-apart" systems and "semitone-apart" systems.

Fourth-apart systems are the most common type of multi-row DBA. On these systems, each row is tuned one-fourth higher than the row next to it. Starting from the outside of the keyboard and moving inward, the outer row is usually named first. For example, on a G/C instrument, the outer row is in the key of G, and the inner row is in the key of C.

In continental Europe, two-row systems in G/C and C/F, as well as three-row systems in G/C/F, are commonly used. Other combinations also exist. In England, during the late 20th century, the D/G configuration became the standard for playing traditional English music, especially for accompaniment in social and Morris dancing.

Three-row systems are also popular in Mexico, the United States (in Conjunto, Tejano, Zydeco, and Cajun music), and Colombia (in Vallenato and Folklor music). Tunings include B♭/E♭/A♭, A/D/G, G/C/F, F/B♭/E♭, and E/A/D. The three-row fourth-apart setup is called the "international system."

Multi-row systems allow players to use more tonalities. However, some notes in the extra rows are "reversals," meaning they are duplicates created by moving the bellows in the opposite direction. This gives players more flexibility in phrasing, as they can choose whether to change bellows direction or harmonize with a chord by selecting notes from different rows. Some playing styles use row-crossing to make the bass side more effective and reduce changes in bellows direction.

To increase flexibility in fourth-apart systems, some systems include notes outside the diatonic scales of each row, called "accidentals." These notes are often played using the buttons at the top of the keyboard, near the player’s chin, below the lowest notes of the scale.

Accidentals may be placed on two extra buttons or a shorter third row of four or more buttons close to the bellows. The Club system developed by Hohner is an example of this. With accidentals and a Gleichton (a unisonoric second-octave note in the middle row), this system allows players to play a full chromatic scale, but only in one direction (draw).

Short rows, or "half-rows," are also used to provide reversals, giving players more flexibility.

In semitone-apart systems, each row is tuned a semitone higher than the row next to it. This setup makes all the notes of the chromatic scale available. As a result, these instruments could be called chromatic rather than diatonic. However, the keyboard’s single action and layout often limit players to a narrower range of keys, even though it is wider than most fourth-apart systems.

The earliest semitone-apart system was C/C♯. Many variations, such as D/D♯ and G/G♯, have been used over time. Since the mid-20th century, two main systems have been widely used: the B/C system, used mainly for Irish and Scottish music, and its larger version, the B/C/C♯ system (now rarely used outside Scotland). Another system is the C♯/D system, which is less common and used mainly in Irish music. Some Irish-American musicians in the mid-20th century used this system with the rows reversed (D/C♯).

Bass systems

Traditionally, one-row instruments have two or four buttons on the bass side, two-row instruments have eight buttons, and three-row instruments have twelve buttons. As mentioned earlier, bass buttons are usually placed in pairs that include a single note and a chord.

Some modern players, especially in France, are creating instruments with more complex bass systems that have as many as 16 or 18 buttons. These systems sometimes do not follow the single-action principle and may have buttons that play only bass notes instead of pairs of bass notes and chords.

The B/C/C♯ system, also called the British Chromatic System, used in Scotland is an example of an instrument with a double-action bass side and a single-action melody side. These instruments often include a complete Stradella bass system, which is also found on piano accordions and chromatic button accordions.

Geographical variations on the DBA theme

Different types of the DBA have been created in various parts of the world. These include the Russian garmon, the Steirische Harmonika or Slovenian-style accordion, which is popular in Alpine areas of Europe, the Swiss Schwyzerörgeli, and the Basque trikitixa. The Swiss Schwyzerörgeli and Basque trikitixa both have parts that allow for both single-action and double-action playing. A common type of Italian organetto has one row of buttons for the main melody, and a small second row with two to four buttons (usually smaller than those on the main row) that are used only for playing notes backward.

Advantages and disadvantages of the diatonic system

DBAs have two main advantages compared to chromatic accordions, such as piano accordions and chromatic button accordions. These are: 1) smaller size and lighter weight, and 2) the natural rhythmic effects from the push-pull action.

The difference in size and weight comes from how accordion reeds work. Reeds produce sound only when air moves through them in one direction. This means that for any key or button, two reeds are needed: one to sound when pressed, and one to sound when drawn. A double-action instrument, which plays the same note on both press and draw, requires two reeds for each note. A single-action instrument, which plays different notes on press and draw, only needs one reed per note. Because of this, double-action instruments need about twice as many reeds as single-action instruments, making them larger and heavier. For example, a piano accordion needs 8 keys (16 reeds) to play a scale from C to C', while a DBA in C needs 4 buttons (8 reeds) to play the same notes. This size and weight advantage is reduced in more complex, multi-row DBAs.

The push-pull action of a DBA creates natural rhythmic patterns that work well with lively dance music, especially traditional styles. On some multi-row instruments, players can use a row-crossing style to smooth out the rhythm. On semitone-apart systems, the playing style may need to be smoother depending on the key of the music. The close spacing of notes on a DBA also makes it easier to play fast tunes, such as Irish reels or Swiss dances, compared to the more spread-out keyboards of chromatic or piano accordions.

A downside of the diatonic system is that it is difficult to play in many different keys. Adding extra rows or more complex bass systems to improve this often increases the instrument’s size and weight, which can worsen the problem. For example, some French musicians use 18-bass three-row DBAs, and B/C/C♯ accordions with 120-button Stradella basses. These instruments can be as large and heavy as medium-sized piano or chromatic accordions.

Notable players

• Basque Country: Kepa Junkera
• Belgium: Wilfrid Moonen, Rik Boone, Louis Spagna, Toon Van Mierlo, Pascale Rubens
• Brazil: Renato Borghetti, Gilberto Monteiro
• Colombia: Israel Romero (Vallenato), Aniceto Molina (Cumbia), Alfredo Gutiérrez (Vallenato), Alejo Durán (Vallenato), Emiliano Zuleta (Vallenato), Colacho Mendoza (Vallenato), Lisandro Meza (Porro and Cumbia), Antonio Rivas (Vallenato)
• Dominican Republic: Krency Garcia (Merengue Tipico), Tatico Henriquez (Merengue Tipico)
• England: Jack Hogsden, Hazel Askew, Andy Cutting, Tim Edey, John Kirkpatrick, Brian Peters, Saul Rose, John Spiers, Rod Stradling, John Tams, Tim van Eyken, Will Hampson, Cohen Braithwaite-Kilcoyne, Martin Ellison, Paul Young, Will Pound, Frankie Insley, Archie Churchill-Moss, Max Thomas of Skinny Lister
• Ireland: Joe Burke, Bobby Gardiner, Joe Cooley, Tony MacMahon, James Keane, Joe Derrane, Jackie Daly, Máirtín O'Connor, Sharon Shannon, Johnny O'Leary, Johnny Connolly
• Italy: Denis Novato, Riccardo Tesi, Ambrogio Sparagna [it], Massimiliano Morabito, Donatello Pisanello
• Mexico: Ramón Ayala (Norteño)
• Netherlands: Frans Tromp
• Newfoundland: Harry Hibbs, Minnie White, Frank Maher
• Norway: Rannveig Djønne, Tom Willy Rustad [no]
• Scotland: Peter Wyper, Jimmy Shand, Will Starr, Fergie MacDonald
• Slovenia: Lojze Slak
• USA: John Kimmel, Joe Derrane, Huddie Ledbetter, Marc Savoy (Louisiana Cajun), J Boozoo Chavis (Louisiana zydeco), Flaco Jimenez (conjunto), Mojo of Mojo & The Bayou Gypsies (zydeco, Cajun), Willi Carlisle, David Hidalgo, Jeffery Broussard, Geno Delafose, John Delafose, Joe Falcón, Keith Frank, Santiago Jiménez Jr., Cedric Watson

Repertoire

• The piece "Dances from a New England Album," written in 1856 by William Bergsma for an orchestra, uses the melodeon in movements 1 through 3 and the harmonium in movement 4.