The lines below come from the song Embracing Accusation by Shane and Shane. In this song they talk about Satan's accusations. I'm not a big fan of the song itself (musically), but I really like the way the song ends with Satan singing an old song of which he forgot the chorus!
Oh the devil’s singing over me
An age old song
That I am cursed and gone astray
Singing the first verse so conveniently
He’s forgotten the refrain--
From "Embracing Accusation" by Shane and Shane. Words by Shane Barnard.