Mashup

Mashups (previously known as "Bastard pop") are a kind of music that requires 2 or more songs, usually laying the vocal track from one song over the instrumental from another.

List of Mashups
It is of note that all of the songs in this list can be catigorized as "A vs. B", meaning simpily that vocals from one song is placed over the music from another song to create a third one. In some cases, howver, more then one song has been used.