The rap band 2 Live Crew created a parody/remake of Roy Orbison's copyrighted song, "Oh Pretty Woman."  While the group offered to pay licensing fees for their use of the song, Campbell (who owned the copyright) declined their offer.  The band released their version in spite of Campbell's refusal, and he brought suit against them for copyright infringement.  In defending against the suit, 2 Live Crew claimed that their parody was a form of social commentary, and thus fell within the "fair use" exception to copyright protection.  The Supreme Court considered four factors in determining whether the use of copyrighted material was "fair use": (1) the purpose and character of the use -- whether the band's use of "Oh Pretty Woman" was so "transformative" that it created a totally new and different work which did not supplant the original;  (2) the nature of the copyrighted work -- whether the copyrighted version was original, and thus enjoyed heightened protection;  (3) the amount and substantiability of the portion used -- whether the band used too substantial a portion of the original song in their remake;  and (4) the effect of the use on the market for the original -- whether the rap version of the song was found not to have a negative effect on the market for the original or licensed derivatives of the original.  The case was ultimately remanded to a lower court to decide the "market effect" issue, but this four-part test has become the standard for applying the "fair use" exception to parody.