“A cover song”
I could say something about songs that people don’t even realize are covers. A good example is “Fly Me to the Moon”; there is a very real chance that by now the 50 billion recordings associated with Neon Genesis Evangelion might have left some people unaware that song had prior existence. Okay, probably not too many; Frank Sinatra is still famous, and his version was even used by the Apollo program, becoming the first music heard on the moon. But did you know that Frank Sinatra’s version wasn’t the original either? The song was written by Bart Howard and first recorded by Kaye Ballard in 1954, 10 years before Sinatra.
Megumi Hayashibara’s version is a cover of a cover of a cover.
(uploaded by Miguel Concepcion)
There are bands that are all about covers. I really like Animetal and Animetal USA, who, as their names imply, do metal covers of anime songs.