Gangsta rap is a kind of hip hop, most importantly characterized by a lyrical focus on macho sexuality, physicality, and a dangerous criminal image. Though the origins of gangsta rap can be traced back to the mid-1980s style of Philadelphia's Schoolly D and the West Coast's Ice-T, the style broadened and came to apply to many different regions in the country, to rappers from New York, such as Notorious B.I.G. and influential hip hop group Wu-Tang Clan, and to rappers on the West Coast, such as Too Short and N.W.A. A distinctive West Coast rap scene spawned the early 1990s G-funk sound, which paired gangsta rap lyrics with a thick and hazy sound, often from 1970s funk samples; the best-known proponents were the rappers 2Pac, Dr. Dre, Ice Cube, and Snoop Dogg. Gangsta rap continued to exert a major presence in American popular music through the end of the 1990s and early into the 21st century.