@McTag,
Found this on wikipedia.
Rhythm and blues is a genre of popular African American music created in the 1940s to the 1950s. The term was originally used by record companies to refer to recordings marketed predominantly to urban African Americans, at a time when "urbane, rocking, jazz based music with a heavy, insistent beat" was becoming more popular.
The term has subsequently had a number of shifts in meaning. In the early 1950s and beyond, the term "rhythm and blues" was frequently applied to blues records, for instance, John Lee Hooker's "I'm in the Mood" became number-one on Billboard R&B Music Charts. Starting in the 1960s, after this style of music contributed to the development of "rock and roll", the term "R&B" became used - particularly by white groups " to refer to music styles that developed from and incorporated electric blues, as well as gospel and soul music. By the 1970s, "rhythm and blues" was used as a blanket term for soul and funk. The modern evolution of R&B is named "Contemporary R&B".
