In many Asian countries, especially India, accordions continue to be an integral part of popular music. Contemporary accordions were patented in Austria by the early 19th century, the accordion is part of the wind family. The keyboard or buttons allows you to play specific pitches created by the vibrating reeds. The concertina was invented by Sir Charles Wheatstone in 1829, and marketed extensively after 1836. By the mid 19th century it became a favorite among popular musicians and Salvation Army bands throughout the British Isles.
Accordions are extremely versatile.
The New Grove Dictionary of Musical Instruments. Stanley Sadie, ed. Summer '94 Timson, Chris. Concertina FAQ , 1996.