Rhythm and blues is a popular music genre combining jazz, gospel, and blues influences.

Jerry Wexler of Billboard magazine coined the term rhythm and blues in 1948 as a musical marketing term in the United States. It replaced the term "race music", which originally came from within the black community, but was deemed offensive in the postwar world. Writer/producer Robert Palmer defined rhythm & blues as "a catchall term referring to any music that was made by and for black Americans". He has used the term R&B as a synonym for jump blues. Lawrence Cohn, author of Nothing but the Blues, writes that rhythm and blues was an umbrella term invented for industry convenience. According to him, the term embraced all black music except classical music and religious music, unless a gospel song sold enough to break into the charts.

for Contemporary R&B, see http://www.last.fm/tag/rnb

More information: Wikipedia.