R&B Music: Rhythm and blues (R&B, Soul) is a popular black music genre of US origin. Rooted in the 'urban blues' style of the early 1930s and influenced by the black jazz orchestras of the Swing era, R&B emerged in the 1940s initially in the form of small-band 'jump' music with novelty-type vocalists and jazz-based hornmen and organists.
Today it is one of the most popular musical styles amongst all people. Although R&B comprises an array of jump and club blues, rock and roll, doo-wop, soul (Amy Winehouse, Mariah Carey), Motown, funk (James Brown, Black Eyed Peas), disco and rap; there may also be undertones of jazz, gospel and even country style music as well.
Rock Music: Rock music is a loosely defined genre of popular music that entered the mainstream in the mid 1950s. It has its roots in 1940s and 1950s rhythm and blues, country music (Kenny Rogers) and also drew on folk music, jazz (Louis Armstrong), and classical music.
Many rock groups consist of a guitarist, lead singer, bass guitarist, and drummer, forming a quartet. Some groups omit one or more of these roles and/or utilize a lead singer who plays an instrument while singing, forming a trio or duo; others include additional musicians such as one or two rhythm guitarists and/or a keyboardist. All of these people create a simple, blues-based song structure that was fast, danceable, and catchy.