Samba
Although samba exists throughout Brazil – especially in the states of Bahia, Maranhão, Minas Gerais, and São Paulo – in the form of various popular rhythms and dances that originated from the regional batuque of the eastern Brazilian state of Bahia, a music form from Cape Verde, samba is frequently identified as a musical expression of urban Rio de Janeiro, where it developed during the first years of the 20th century. Early styles of samba - and specifically samba de roda - are traced back to the Recôncavo region of Bahia during the 17th century, and the informal dancing following a candomblé ceremony. It was in Rio de Janeiro that the dance practiced by former slaves who migrated from Bahia came into contact with and incorporated other genres played in the city (such as the polka, the maxixe, the lundu, and the xote), acquiring a completely unique character and creating the "samba carioca urbana" (samba school) and "carnavalesco" (Carnaval school director). Samba schools are large organizations of up to 5,000 people which compete annually in the Carnival with thematic floats, elaborate costumes, and original music.
Rumba
In the US, the term "rhumba" (anglicised version of rumba), began to be used during the 1920s to refer to ballroom music with Afro-Cuban music themes, particularly in the context of big band music. This music was mostly inspired by son cubano, while being rhythmically and instrumentally unrelated to Cuban rumba. By the 1930s, with the release of "The Peanut Vendor", the genre had become highly-successful and well-defined. The rhumba dance that developed on the East Coast of the United States was based on the bolero-son. The first rumba competition took place in the Savoy Ballroom in 1930. Nowadays, two different styles of ballroom rumba coexist: American-style and International-style.
During the 1940s and 1950s, the Mexican and American film industry expanded the use of the term rumba as rumbera films became popular. In this context, "rumberas" were Cuban and Mexican divas, singers and actresses who sang boleros and canciones, but rarely rumbas. Notable "rumberas" include Rita Montaner, Rosa Carmina, María Antonieta Pons and Ninón Sevilla.