[Q| Here's another mash-up theme song, this time from Warner Brothers.
At the beginning of each WB movie, the theme of "As Time Goes By" (from "Casablanca") is heard as the WB shield ripples across the screen.
As the lyrics are sung, it's easy to morph into "I've Grown Accustomed to Your Face" from "My Fair Lady".
"Hearts filled with passion, jealousy and hate
Woman needs man and man must have his mate..."
"Your smiles, your frowns
Your ups, your downs..."
I suspect one can morph back to the original song.