Rhythm and Blues often abbreviated as R&B, is a popular genre of music that originated in African-American communities in the 1940s. 

The great migration of Black Americans to the urban industrial centers of Chicago, New York and Los Angeles in the 1930s created a new market for jazz, blues and related genres of music. 

Precursors of Rhythm and Blues came from Jazz and blues which took the American stage in 1930s after the migration of black Americans to the mentioned cities and this was made popular by the music of Harlem Hamfats, Lonnie Johnson and T-Bone Walker among others. 

The latter coincided with the increasing emphasis and popularity of electric guitar as a lead musical instrument as well as piano and saxophone.

In this musical type, the bands playing R&B usually spread the message of African-American experience of pain, quest for freedom and joy. This was played in a very slow tone, hence the genre being slow and not speedy like rap or others. 

However, the term "Rhythm and Blues” has undergone various shifts: In 1950s, this style of music contributed to the development of rock and roll, while others referred it to music styles that developed from and incorporated electric blues, as well as gospel and soul music. 

In the 1960s, the R&B became so popular that the British rock bands such as the animals and the rolling stones were referred to and promoted as being R&B bands. 

In 1980s, a new style of R&B developed and was known as "Contemporary R&B”, combining rhythm and blues with pop, soul, funk, disco, hip hop and electronic music.