Illegal music

Overview
Illegal music is music which cannot be legally released, typically due to financial barriers to obtaining the necessary permissions from each of the owners of the copyrights for the audio samples used (almost always one of the "big five" record companies which control the majority of the music industry).

Such music is an issue for a number of reasons, including:
 * Unavailability: Many people would like to legally obtain copies of it, as they find the works to be entertaining in their own right and in a manner distinct from the entertainment value of the source works
 * Lack of compensation for "illegal" artistic work:
 * No mechanism exists for providing financial proportionate reward to the artists, thus leaving them uncompensated for their expenses and creative effort
 * The creators of such works often do not find out about copyright conflicts until after they have already invested all the money and effort into producing the work in question; being unable to release the work, they are unable to recoup that investment
 * Creators of such works may have to spend considerable amounts of money in court to defend themselves against even worse fines for copyright infringement, further depleting their financial resources

Works

 * American Edit by "Dean Gray", an album of mashups of songs by neopunk artists Green Day with songs and material by other artists
 * The Grey Album by Danger Mouse, an album of mashups derived from an a cappella version of rapper Jay-Z's The Black Album combined with instrumentals from The Beatles' album The Beatles (aka The White Album)
 * "Kryptonite Werewolves of Alabama" by Woozalia, a mashup of "Werewolves of London", "Sweet Home Alabama" and "Jimmy Olsen's Blues"