Contemporary R&B, also known as simply R&B, is a music genre that combines elements of rhythm and blues, soul, funk, pop, hip hop and dance.
Contemporary R&B has a polished record production style, drum machine-backed rhythms, an occasional saxophone-laced beat to give a jazz feel (mostly common in contemporary R&B songs prior to the year 1995) and a smooth, lush style of vocal arrangement. Electronic influences are becoming an increasing trend and the use of hip hop or dance-inspired beats are typical, although the roughness and grit inherent in hip hop may be reduced and smoothed out. Contemporary R&B vocalists are often known for their use of melisma, popularized by vocalists such as Michael Jackson, R. Kelly, Stevie Wonder, Whitney Houston and Mariah Carey.
( Source: Wikipedia http://en.wikipedia.org/wiki/Contemporary_R%26B )