Diatonic accordions are one of the most widely-used types of accordions and are frequently found in folk traditions across various regions, from Irish traditional music (melodeon) to Cajun, Zydeco and Tex-Mex music.
A two row diatonic accordion features an outer row with one key and an inner row a semitone higher, which enables it to play every note on the chromatic scale. Additional notes may be activated through switches called couplers.
Keyboard
Accordions are bellows-driven free reed aerophones that produce sound when air passes over their reeds, producing sound when air passes over them. They combine a melody section (known as keyboard or discant) on the right-hand side with accompaniment or basso continuo functionality on the left; musicians play melody using buttons or keys arranged diatonically scales and create chromatic tones by combining notes from multiple rows on their keyboards.
Some diatonic button accordions, including the Russian garmon and German-style schallplatten accordions, boast bisonoric features, which allows each key to produce two notes depending on whether it is pushed or pulled. Other such accordions are Switzerland Schwyzerorgeli organetto organetto and Basque trikitixa accordions.
Modern innovations for accordions include improved internal construction methods to increase tone and stability, more buttons than before to enable more complex harmonies and bass structures, and popularization by accordionists such as Huddie “Leadbelly” Leadbetter and Luizinho Calixto who have created new repertoire on them.
Bellows
The bellows, also referred to as ‘the lungs, are an integral component of an accordion and act as its heart. By pressing a button or lever on an accordion’s casing/frame, air passes through compressed bellows into its set of reeds that vibrate creating sound waves.
There are various kinds of accordions, both diatonic and chromatic. Diatonic accordions are specifically designed to produce music in one key and typically feature 7 tones on their diatonic scale; on the other hand, chromatic ones have the capability of playing any note from its respective chromatic scale.
Bandoneon (the predominant type of accordion used in tango music) is a single action accordion that changes pitch depending on which way the bellows are pushed or pulled; unlike diatonic accordions which don’t alter button pitches when changing directions of bellows; both sounds can be combined using registers to produce richer tones.
Reeds
Reeds are essential components of an accordion and its sound; they’re made from cane that is both thick and stiff for added strength, grading graded according to strength. A double-action instrument (one that plays different notes upon pressing or drawing keys or buttons) requires two reeds per key or button, making the instrument much larger and heavier than with single action accordions.
Reeds will last longer if you sand them with coarse grit before playing, then lightly file to smooth down before light filing to smooth them back out again. Rotate reeds after every practice session and generally go one strength stronger from what was first chosen as your initial reed.
Some accordions feature multiple reeds for each key, known as voices. As more voices exist, the louder and more notes you can play at once; an example would be the bisonoric bandoneon which plays two separate notes depending on whether you push or pull on its bellows.
Pitch
Diatonic accordions utilize a complex system of buttons and keys that produces one or more notes from the diatonic scale. On bass-side keyboards, usually two pairs are arranged with one button sounding chord fundamentals while another produces either major or minor triads.
Most diatonic accordions are bisonoric; however, there are exceptions such as the two-row chromatic button accordion and some garmons that feature unisonoric characteristics; additionally there are accordions like the Schwyzerorgeli and Trikitixa which combine both characteristics.
A standard quint-tuned box is typically tuned to approximately twenty pitches, from low sol to high mi. However, some players have expanded the range on their accordions by either adding rows or tuning their boxes differently; Henry Doktorski offers this approach in his “How to Play Diatonic Button Accordions”, Volume three series.