Originating in Brazil in the early XX century, Umbanda is a religion that blends Catholicism, Kardecist Spiritualism and Afro-Brazilian traditions. It is not a "New Religion Movement", although it can be viewed as such when transplanted to a cultural context other than that of Brazil.
Umbanda is a syncretic religion, an attempt by the lower-class suburban black population of Rio de Janeiro to keep as much as possible of its rituals under the cover of Catholic worship.
Most of the appeal of Umbanda comes from its lose morality -- not very far from Crowleys "do what thou willst" -- and the shocking dissimilarity of its rituals.
Umbanda is a polytheist religion which worships some of the African Orishas that were still recalled by the blacks after centuries in Brazil. Each Orisha is associated with a Catholic saint, under whose name worshipping is done. For insance, Ogum, the blacksmith god, is associated with Saint George, while Yansan, with Saint Barbara. God himself is regarded as a Deus otiosus and is seldom preached to.
As in Candomblé, the cult used to be carried in rustic temples called Terreiros --- large round spaces surrounded by wooden seats, covered with palm-leaf roof. Music (percussion and chanting) played a central role. The head of the Terreiro is called "pai-de-santo" ("saint father") or "mãe-de-santo" ("saint mother") and the followers are usually called "filhos-de-santo" ("saint children", masculine plural form).
Worshipping involved bloodless sacrifices to the deities (black hens, cheap wine, farofa, cachaça, popcorn, cigarrettes, hard cider and other types of foodstuffs of beverages; depending on the "saint") and had complex initiation rituals. "Pais de santo" and "Mães de santo" also played Divination using the "Jogo de Búzios" (the reading of the supposed arrangement of small sea shells), gave advice to those who sought it and produced "strong prayers" (Rezas fortes) for those who needed them to evade troubles with the police, lack of money, sexual impotence and other nuisances, usually attributed to the Evil Eye.
Until the half of the XX century, all Afro-Brazilian religions were considered as crimes but they became quite popular later on, as many popular novelists and songwriters wrote or sung about them. Most of Jorge Amado's works, for instance, are heavily concerned with the trials and tribulations of the Afro-Brazilians and helped foster tolerance towards Umbanda. From the 1960s and on, many and many popular songs about Umbanda and the other Afro-Brazilian religions became popular too. Among the famous Brazilian composers who wrote about it, Tom Jobim, Toquinho, Vinícius de Moraes, Geraldo Vandré and Clara Nunes are the most widely know abrowd. In tghe 1970s, poet Vinicius de Moraes married his last wife, Gesse, in an Umbandist ceremony witnessed by many prominent figures of Brazilian culture and politics (he had also been a diplomat).
Umbanda is juxtaposed with Quimbanda and distinct from both Macumba and Candomblé.