From David Spencer's Media Spin : Observations about media in Canada
R&B is Rhythm and Blues music. R&B was coined as a musical marketing term in the United States in 1949 by Jerry Wexler at Billboard magazine, and was used to designate upbeat popular music performed by African American artists that combined jazz, gospel, and blues. It replaced the term race music, which was deemed offensive, as well as the Billboard category name "Harlem Hit Parade," in June of 1949, and was initially used to identify the rocking style of music that combined the 12 bar blues format and boogie woogie with a backbeat, later known as rock and roll. In 1948, RCA Victor was marketing black music under the name "Blues and Rhythm," but the words were reversed by Wexler of Atlantic Records, the most aggressive and most dominant label in the R&B field in the early years. By the 1970s, rhythm and blues was being used as a blanket term to describe soul and funk as well. Today, the acronym "R&B" is almost always used instead of "rhythm and blues", and defines the modern version of the soul and funk influenced African-American pop music that originated with the demise of disco in 1980.
For more informationplease visit http://en.wikipedia.org/wiki/R&B