Hip hop music, also called hip-hop or rap music, is a music genre formed in the United States in the 1970s that consists of a stylized rhythmic music that commonly accompanies rapping, a rhythmic and rhyming speech that is chanted. It developed as part of hip hop culture, a subculture defined by four key stylistic elements: MCing/rapping, DJing/scratching, break dancing, and graffiti writing. Other elements include sampling (or synthesis), and beatboxing.