Sampling involves reusing portions of existing sound recordings in new songs. It has been an important part of genres like hip hop since the 1970s but is controversial from a legal perspective. Legally, sampling is evaluated on a case by case basis and may be considered fair use, as was determined in the landmark 1994 Supreme Court case Campbell vs. Acuff-Rose regarding 2 Live Crew's parody of a Roy Orbison song. Famous sampled songs include "Amen Break" and Marvin Gaye's "Got to Give It Up".