The relationship between graffiti and hip hop culture arises both from early graffiti artists engaging in other aspects of hip hop culture, Graffiti is understood as a visual expression of rap music, just as breaking is viewed as a physical expression. The 1983 film "Wild Style" is widely regarded as the first hip hop motion picture, which featured prominent figures within the New York graffiti scene during that period. The book "Subway Art" and the documentary "Style Wars" were also among the first ways the mainstream public were introduced to hip hop graffiti. Graffiti remains part of hip hop, while crossing into the mainstream art world with exhibits in galleries throughout the world.