Diatonic accordions, also referred to as melodeons or German accordions, consist of ten buttons in a row as their keyboard; on their left or accompaniment side are chords for accompaniment purposes.
Right keyboard contains diatonic scale reeds in certain keys while left keyboard provides chord bass notes and chord progressions. Chromatic button accordions offer every note via numerous octaves’ worth of reeds but at the cost of size and weight.
Keys
Single row diatonic accordions, commonly known as melodeons, are squeeze button instruments with specific key arrangements. For example, three row models might contain buttons for C, F and G keys or Eb, B and F keys; this enables players to move through different push and pull tones easily without changing fingerings – this system is known as the International System and commonly found in Norteno, Conjunto, and Tex-Mex music genres.
Notes on the right-hand keyboard can be used to form major triad sequences when an accordion is in its closed state, while when its bellows open each button produces its own chord in accordance with its key of composition.
Diatonic accordions come in many varieties, including three and four row versions that follow a regular pattern, digital models offering both diatonic and chromatic playing options, and more. Tom Waits was an renowned acoustic accordion player who used such models, while in 2012 Johnny Kongos and his brothers from Arizona became internationally acclaimed piano accordion players.
Reeds
Diatonic accordions may only have limited keys, yet can still be very effective and enjoyable to play. Their bisonoric keyboard allows notes to change based on bellows direction (pull/push). Their right hand row typically features two different reed pitches for every key while their left hand has a 96 bass standard system with one note that doesn’t change during each key change.
Button accordions with one diatonic row are known as melodics or melodeons, while instruments with multiple rows are known as quarte or four voice accordions. Using switches known as buttons, couplers or registers to activate each reed rank allows this instrument to play a full range of chromatic scales; additionally it requires at least two reeds for every button or key which makes this style of accordion larger and heavier than its single action counterpart; additionally it requires its own distinct playing technique which makes these instruments popular with folk musicians as well as dance groups.
Bellows
The bellows is the primary means of producing accordion sound, creating a vacuum which draws air into the instrument through vibrating internal reeds to vibrate them and produce sound waves. Sound production directly correlates to how much air enters or exits through its apertures in relation to sound generated.
Single row diatonic accordions like the melodeon are widely used in Irish and Celtic music, as well as Cajun music (known as Zydeco). Two row diatonics and multi row instruments like an Italian Organetto are popular with professional musicians for their range of sounds and complex harmonies.
Most accordions are diatonic button or bisonoric, meaning their right-hand keys produce different notes depending on whether they’re pressed or pulled (unlike unisonoric accordions with unisonoric key layouts). This happens because each button’s pallet opens and closes according to bellows movement – similar to how mouth harmonicas operate.
Keyboard
The treble-side keyboard contains 25 buttons arranged in two rows, while the bass-side keyboard features 8 pairs of buttons, each representing either the root note or its related chord on a scale. Two short additional rows called “accidentals” provide notes outside diatonic scales, giving more flexibility to players. Garmon accordions typically use Helikon bass reeds which produce distinctive tuba-like bass notes.
Diatonic accordions are excellent instruments for traditional music styles such as Cajun, Zydeco and Irish folk music, but its limitations make it challenging to play modern offshoots of these genres. Because of this difficulty in performing modern forms of these genres, many musicians prefer playing chromatic accordions which have multiple keys and several octaves worth of reeds per key – though these chromatic instruments tend to be much heavier than diatonic accordions.