Rock music is a genre of popular music originating in the 1950s; a blend of Black rhythm-and-blues with White country-and-western; usually featuring vocals (often with vocal harmony), electric guitars, a bass guitar, and a strong back beat; other instruments, such as the saxophone, trumpet, and trombone are common in some styles, however, horns have been omitted from newer subgenres of rock music since the 90s. The genre of rock is broad, and its boundaries loosely-defined, with distantly related genres such as soul sometimes being included.