200px|thumb|right|Diatonic button accordion (German make, early 20th century) A button accordion is a type of accordion on which the melody-side keyboard consists of a series of buttons. This differs from the piano accordion, which has piano-style keys. Erich von Hornbostel and Curt Sachs categorize it as a free reed aerophone in their classification of instruments, published in 1914. The sound from the instrument is produced by the vibration of air in reeds. the button accordion's buttons are on the front of the instrument, while the concertina's are on the sides and pushed in parallel with the bellows.
Main components
All accordions and concertinas have three main components: the reeds, bellows, and buttons or keys. Pushing or pulling the bellows slower or faster makes the sound softer or louder, respectively. on both the treble and bass sides. In modern accordions, the free reeds are generally made of tempered steel.
Variations
Button accordions are found with a wide variety of keyboard systems, tuning, action, and construction.
The diatonic button accordion is bisonoric, meaning when a button is pressed, the note sounded changes depending on whether the bellows are being expanded or contracted. The diatonic button accordion is the most popular type of button accordion, and appears in many cultures, especially in folk music. Mexican norteño musicians prefer accordions with more vibrato, and Texan musicians favor less vibrato. It was a popular instrument with the Cajuns and the French-speaking creoles.