Many of the American Style dances developed through the strong influence of Arthur Murray, who established a chain of dance studios, for which these dances were formalized. All the dances are developed from left turning patterns first. One of the most noticeable differences from the International Style dances is that you can add open position figures and under arm turns in the Smooth dances. The two American Style dance categories are: Smooth which includes Waltz, Tango, Viennese Waltz, and Foxtrot; and Rhythm which includes Cha Cha, Bolero, Rumba, Mambo, and Swing. Both the Standard and Rhythm dances are popular on the social as well as the competitive floor.