A
mashup (also
mesh,
mash up,
mash-up,
blend,
bootleg and
bastard pop/rock) is a song or composition created by blending two or more pre-recorded songs, usually by overlaying the vocal track of one song seamlessly over the instrumental track of another. To the extent that such works are "
transformative" of original content, they may find protection from copyright claims under the "
fair use" doctrine of copyright law.