Critics of rock and roll songs have occasionally claimed that rock musicians have recorded backward messages into their songs, and that these messages contain subliminal commands that encite their listeners to commit acts of violence. The general population (espcially among fans of rock-and-roll music) usually scoffs at the idea that hidden commands are recorded in rock music, and this idea has become an urban legend.
The most famous alleged backward message in a rock and roll song is based on a lyric from the song Stairway to Heaven by Led Zeppelin. When the words "...it makes me wonder" are played backwards, the resulting noise is a garbled phrase that some claim is actually the phrase "My sweet Satan."
Advocates of the theory that Paul McCartney died in the 1960s claim that the hidden message "Paul Is Dead" is found by running the album Sgt. Pepper's Lonely Hearts Club Band backwards.
British heavy metal band Judas Priest, was sued over a 1985 suicide pact made by two Nevada schoolboys. One of the two youths survived, and the lawsuit by the boy's families claimed that a 1978 Judas Priest album contained hidden messages. The words "Do it" allegedly can be heard when the record is played backwards, and the letters S U I (for "suicide") are in the sleeve artwork. The case was dismissed after evidence was introduced that the boys had grown up in "violent and depressed" surroundings.
So-called backward masking is a great concern in some conservative Christian circles.
Several musicians have deliberately recorded backward messages into their songs, as a way of making an artistic statement, and also to have fun at the expense of their critics. On the 1991 album Amused to Death by Roger Waters, Waters deliberately recorded a backward message that was meant to criticize film director Stanley Kubrick. (Kubrick had refused to let Waters sample the breathing sound from 2001: A Space Odyssey.) Another famous, deliberately recorded, backwards message comes from the beginning of the Electric Light Orchestra song "Fire on High", where the mysterious deep mumbling reverses to "The music is reversible, but time is...turn back! turn back! turn back!", ostensibly a shot at the hysteria surrounding "reversed speech" at the time the album was released.
The Christian rock group Petra in their song Judas Kiss included the message "What are you looking for the devil for, when you ought to be looking for the Lord?".
It is worth noting that, given a randomly generated series of syllables spoken in a variety of accents, a two-syllable pair that can be liberally interpreted as "Satan" is very easy to generate. Therefore, any individual with a small amount of creative interpretation skills could play virtually any song with vocals backwards and uncover "Satanic messages". This fact has been exploited by defense attorneys in "backwards messaging" court cases, who often disprove allegations by "uncovering Satanic messages" in songs by Christian artists, most famously Amy Grant.