Cinatas?

The Beatles were involved in the spread of backmasking both as a recording technique and as the center of a controversy. The latter has its roots in an event in 1969, when WKNR-FM DJ Russ Gibb received a phone call from a student at Eastern Michigan University who identified himself as "Tom". The caller asked Gibb about a rumor that Beatle Paul McCartney had died, and claimed that the Beatles song "Revolution 9" contained a backward message confirming the rumor. Gibb played the song backwards on his turntable, and heard "Turn me on, dead man … turn me on, dead man … turn me on, dead man…"

Backmasking has also been used to record statements perhaps too critical or explicit to be used forwards. Frank Zappa used backmasking to avoid censorship of the track "Hot Poop", from We're only in it for the Money (1968). The released version contains at the end of its side "A" the backmasked message "Better look around before you say you don't care. / Shut your f...ing mouth 'bout the length of my hair. / How would you survive / If you were alive / shitty little person?" . This profanity-laced verse, originally from the song "Mother People", was censored by Verve Records, so Zappa edited the verse out, reversed it, and inserted it elsewhere in the album as "Hot Poop" (though even in the backward message the word "fucking" is censored). More.
And a backmasking tsil here.