Gangsta rap or gangster rap, initially called reality rap, is a subgenre of hip hop music that emerged in the mid- to late 1980s as a distinct but highly controversial rap subgenre, whose lyrics assert the culture and values typical of American street gangs and street hustlers. (Many gangsta rappers flaunt associations with real street gangs, like the Crips and the Bloods.) Gangsta rap's reputed, earliest pioneers were Philadelphia rapper Schoolly D and Los Angeles rapper Ice-T and the genre was taken to new heights in 1988 by rap group N.W.A. By 1992, via record producer Dr. Dre, rapper Snoop Dogg and their pioneering G-funk sound, gangsta rap had taken the rap genre's lead and become mainstream, popular music.