Hip hop music, developed in the South Bronx in the early 1970s, has long been tied to social injustice in the United States, particularly that of the African American experience. Hip hop artists have spoken out in their lyrics against perceived social injustices such as police brutality, poverty, mass incarceration, and the war on drugs. The relationship between hip hop music and social injustice can be seen most clearly in two subgenres of hip hop, gangsta rap and conscious rap.