[rith
-uhm-uhn-blooz] 
| a folk-based but urbanized form of black popular music that is marked by strong, repetitious rhythms and simple melodies and was developed, in a commercialized form, into rock-'n'-roll. |
| rhythm and blues pl.n. (used with a sing. or pl. verb) Abbr. R & B A style of music developed by African Americans that combines blues and jazz, characterized by a strong backbeat and repeated variations on syncopated instrumental phrases. |