Oops ... I think you actually mean Cher's "Do you believe in Love?" don't you Ralphie?

Re the matter of putting a naff singer's voice into tune, there is of course the notorious video of Katie Price (AKA Jordan) and Peter Andre singing some little ditty where she is hideously out of tune in one video ... but another video exists on the net where the voices are both miraculously in tune (both to be found on Youtube).