Rumba is both a family of music rhythms and a dance style that originated in Africa and traveled via the slave trade to Cuba and the New World. The so-called rumba rhythm, a variation of the African standard pattern or clave rhythm, is the additive grouping of an eight pulse bar (one 4/4 measure) into 3+3+2 or, less often, 3+5 (van der Merwe 1989, p.321). Original Cuban rumba is highly polyrhythmic, and as such is often far more complex than the examples cited above.
There are several Social Dances which can be subsumed under Rumba; Rumba itself (also spelled Rhumba) and Bolero, based on Cuban Rumba and Son. In American-style ballroom dancing, bolero is basically a slow version of the International-style back-and-forth (also known as slotted) rumba but without the hip or Cuban motion and with added rise and fall.
American Ballroom rumba ("ballroom" understood in the more general meaning of that word; in the stricter sense we speak of ballroom or latin american dances as two differnet kind of social or competitive dances in Europe) is danced in either a box-step style (which in fact is called "Cuban Rumba" by dancing teachers) or a back and forth style with different hip motions supporting the movements. In Europe, only the latter form has survived (perhaps with the exception of the preliminary use for the very beginner) the "Rumba wars" of the 60`s between french an british dancing teachers, who supported the two versions respectively.
Also, still another variant of Rumba music and dance was popularized in the United States in 1930s, which was almost twice as fast, as exemplified by the popular tune, The Peanut Vendor. This type of "Big Band Rumba" was also known as Rhumba. The latter term still survives, with no clearly agreed upon meaning; one may find it applied to Ballroom, Big Band, and Cuban rumbas.
Confusion about the style of rumba may arise if three essential facts are ignored: First of course is the speed of music, which has internationally decreased significantly since the fifties. That eliminates figures which have become too quick for the slower music and created new ones. Secondly, performing the dance requires attention from the side of the teacher and leads to very different looking appearances on the floor. And thirdly, figures are constantly wandering from one dance to another, because advanced dancers always search for something new.