A diatonic button accordion (DBA) is a member of the free-reed aerophone family of musical instruments. It is a type of button accordion on which the melody-side keyboard contains one or more rows of buttons, with each row producing the notes of a single diatonic scale. The buttons on the bass-side keyboard are most commonly arranged in pairs, with one button of a pair sounding the fundamental of a chord and the other the corresponding major triad (or, sometimes, a minor triad).
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. For example: The chromatic button accordion The diatonic button accordion
The name "Steirische Harmonika" literally translates from German as Styrian accordion, but the use of the adjective steirische stems from the Viennese dialect, where it refers to the folk music in general. There is no relationship to the nearby state of Steiermark, or Styria as it is traditionally called in English, even this types of Accordion are in use there as well.