The accordion family includes a wide variety of styles and forms. The piano, diatonic and chromatic accordions are just a few of the most popular choices. Another important branch on the family tree, the button accordion, has been popular since it was first developed in the late nineteenth century.

The button accordion is an adaptation of an older and more basic instrument called a melodeon. Physically, the button accordion is unique in that it has an extra row of buttons that have been pitched a semi-tone above or below those of the melodeon. It's possible for the musician to manipulate the bellows and actually create two notes from one single button. This is what gives the button accordion greater articulation, and economy of fingering.

With the family of button accordions, there are some variations. The widest array can be found within the areas of tuning, action and basic construction of the individual instruments.

The diatonic is one of the most popular of the button accordion styles. Diatonic accordions have melody-sized keyboards that are limited to the notes of the diatonic scale. Just one key, or a small number of keys, can provide these notes. An interesting aspect of the diatonic accordion as that the bass side usually contains the principal chords of the instrument's key and the root notes of those chords.

Diatonic button accordions are generally bisonoric. This means that every button produces a couple of notes. One note is produced when the bellows are compressed, while the other is produced when the bellows are expanded.

There are some diatonic button accordions, however, that are unisonoric. Each button on the garmon produces the same note, whether the bellows are expanded or compresses. Other diatonics are created in a combination of the two styles.

The chromatic is another popular style of button accordion, with a melody-sized keyboard composed of uniform rows of buttons. These buttons are arranged to provide an increase of the chromatic pitch along the diagonals. The keyboard on the bass side of the chromatic accordion typically uses a Stradella system, one of many free-bass or converter systems.

There are some instruments in this class that are known simply as "chromatic" accordions. Other types, including the piano accordion, can also be fully chromatic. Ever since the chromatic buttons were introduced, this type of accordion has become the choice of many classical music performers. The treble keyboard is denser than that of a piano accordion to provide a much greater musical range.

Various cultures have developed their own versions of modern button accordions, and have adapted their inventions to suit their own traditional styles of music. Russia alone has a number of accordions, such as the Garmon, Saratovskaya Garmonica, Livenka and the very popular Bayan.

If you love the unique sound that an accordion can bring to traditional and popular music, pick up a button accordion and try your hand at playing this age-old and ever-popular instrument.