Rhythm and blues, often abbreviated to R&B, is a genre

Genre

Genre , Greek: genos, γένος) is the term for any category of literature or other forms of art or culture, e.g. music, and in general, any type of discourse, whether written or spoken, audial or visual, based on some set of stylistic criteria. Genres are formed by conventions that change over time...

 of popular

Popular music

Popular music belongs to any of a number of musical genres "having wide appeal" and is typically distributed to large audiences through the music industry. It stands in contrast to both art music and traditional music, which are typically disseminated academically or orally to smaller, local...

 African American music

African American music

African-American music is an umbrella term given to a range of musics and musical genres emerging from or influenced by the culture of African Americans, who have long constituted a large and significant ethnic minority of the population of the United States...

 that originated in the 1940s

1940s

File:1940s decade montage.png|Above title bar: events which happened during World War II : From left to right: Troops in an LCVP landing craft approaching "Omaha" Beach on "D-Day"; Adolf Hitler visits Paris, soon after the Battle of France; The Holocaust occurred during the war as Nazi Germany...

. The term was originally used by record companies to describe recordings marketed predominantly to urban African Americans, at a time when "urbane, rocking, jazz

Jazz

Jazz is a musical style that originated at the beginning of the 20th century in African American communities in the Southern United States. It was born out of a mix of African and European music traditions. From its early development until the present, jazz has incorporated music from 19th and 20th...

 based music with a heavy, insistent beat" was becoming more popular.

The term has subsequently had a number of shifts in meaning.