The Rumba was originally a marriage dance and is now known as "the dance of love." Rumba became a popular ballroom dance and was introduced in the United States about 1933. It is the Americanized version of the Cuban Son and Danzon; it is in 4/4 time. The characteristic feature is to take each step without initially placing the weight on that step. Steps are made with a slightly bent knee which, when straightened, causes the hips to sway from side to side in what has become known as "Cuban Motion." Rumba was the basis for Mambo and Cha Cha in the US and Rumba rhythms have found their way into Country Western, Blues, Rock & Roll and other popular forms of music.