A chromatic button accordion is a type of button accordion

Button accordion

A button accordion is a type of accordion on which the melody-side keyboard consists of a series of buttons rather than piano-style keys. There exists a wide variation in keyboard systems, tuning, action and construction of these instruments...

 where the melody

Melody

A melody , also tune, voice, or line, is a linear succession of musical tones which is perceived as a single entity...

-side keyboard consists of rows of buttons arranged chromatically. The bass-side keyboard is usually the Stradella system

Stradella bass system

The Stradella Bass System is a buttonboard layout equipped on the bass side of many accordions, which uses columns of buttons arranged in a circle of fifths; this places the principal major chords of a key in three adjacent columns...

 or one of the various free-bass system

Free-bass system

A free-bass system is a system of bass buttons on an accordion, arranged to give the performer greater access to playing melodies on the left-hand manual of the instrument and to forming one's own chords, by providing a buttonboard of single-note buttons with a range of three octaves or more, in...

s. Included among chromatic button accordions are the Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

n bayan

Bayan (accordion)

The bayan is a type of chromatic button accordion developed in Russia in the early 20th century and named after 11th-century bard Boyan.-Characteristics:The bayan differs from western chromatic button accordions in some details of construction:...

 and Schrammel accordion

Schrammel accordion

A Schrammel accordion is an accordion with a melody keyboard in the chromatic B-Griff system and a twelve-button diatonic bass keyboard...

. There can be 3 to 5 rows of horizontal treble buttons. In a 5 row chromatic, two additional rows repeat the first 2 rows to facilitate options in fingering.

Comparing the layout to the piano accordion, the advantages of a chromatic button accordion is the greater range and better fingering optionsThe uniform layout allows for uniform fingering and making of chords; meanwhile, the chromatic button layout also allows for alternative fingerings. As the buttons are closer, it is also easier to reach notes that are far apart, such as two octaves apart.. On the other hand, some fingering positions require twisting of the wrist and the aspect of alternative fingering patterns may stunt one in sessions of difficult sight reading.

Throughout the former Yugoslavia

Yugoslavia

Yugoslavia refers to three political entities that existed successively on the western part of the Balkans during most of the 20th century....

 a 6-row chromatic button layout is used based on the B system. It is referred to as dugmetara.