rhythm_and_blues | derivative | disco <sep> rhythm and blues, frequently abbreviated as r&b or r'n'b, is a genre of popular music that originated in african-american communities in the 1940s the term was originally used by record companies to describe 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 in the commercial rhythm and blues music typical of the 1950s through the 1970s, the bands usually consisted of a piano, one or two guitars, bass, drums, one or more saxophones, and sometimes background vocalists r&b lyrical themes often encapsulate the african-american experience of pain and the quest for freedom and joy, as well as triumphs and failures in terms of relationships, economics, and aspirations 
disco is a derivative of rhythm and blues.no information