The sound comes from the instrument thanks to the metal tongues which vibrate by stretching and folding the bellows. It is played with four fingers, without the thumb. This type of harmony is modeled on the double-row German harmonies. After the First World War, harmony spread as a component of folk bands, mainly superseding the bass. A harmonist is able to play independently at a wedding, but so far it is played with a violin and drum or a trumpet and a clarinet. Today it is the most popular in Mazowsze region, area of Łowicz and northern Małopolska.