Assertion: hip hop's music | /r/HasProperty | developed by disc jockeys
Facets:
value: in the late 1970s
type: TEMPORAL
Source sentences:
text: a style of popular music, developed by disc jockeys and urban blacks in the late 1970s, in which an insistent, recurring beat pattern provides the background and counterpoint for rapid, slangy, and often boastful rhyming patter glibly intoned by a vocalist or vocalists.