Polka give way to the two-step and new ragtime dances. Polka dancing enjoyed a resurgence in popularity after World War II, when many Polish refugees moved to the US, adopting this Bohemian style as a cultural dance. Polka dances are still held on a weekly basis across many parts of the US with significant populations of central European origin. It was also found in parts of South America. There are various styles of contemporary polka besides the original Czech dance, which is still the chief dance at any formal or countryside ball in the Czech Republic. One of the types found
Polonaise-Fantaisie (Chopin) and Vladimir Horowitz had been including it in their programs some decades earlier. It is intimately indebted to the polonaise for its metre, much of its rhythm, and some of its melodic character, but the fantaisie is the operative formal paradigm (Samson, 1988), and Chopin is said to have referred initially to the piece only as a Fantasy. Parallels with the Fantaisie in F minor include the work's overall tonality, A-flat, the key of its slower middle section, B major, and the motive of the descending fourth. Jeffrey Kallberg has suggested that the Polonaise-Fantaisie represents a change in Chopin's style