Polka is a type of dance and genre of dance music; it originated in the middle of the 19th century in Bohemia, and is still a common genre of Czech folk music; it is also common both in Europe and in the Americas. In classical music, many polkas were composed by both Johann Strauss; a couple of well-known ones were composed by Bedrich Smetana.
There are various styles of contemporary polka. Of the US types, the North American "Polish-style polka" has roots in Chicago, and can be identified as 'Chicago honky' and 'Chicago push' styles. North American "Slovene-style polka" is fast and features piano, accordion, and is associated with Cleveland. North American "Dutchman-style" features an oom-pah sound, often with a tuba, and has roots in the American midwest. "Conjunto-style" has roots in Northern Mexico and Texas, and is also called Norteno.
Some polka artists: