Singing Fish

Jimmy: "Hey, Mike! How's your new pet fish doing? You told me he was
really something special."

Mike: "To tell the truth, I'm really disappointed in him. The guy who
sold him to me said I could teach him to sing like a bird."

Jimmy: "What? You bought a fish because you thought you could teach him
to sing like a bird? That will never happen."

Mike: "That's what you think! It just so happens this fish CAN sing. The
thing is, he's terribly off-key and it's driving me crazy. Do you know
how hard it is to tuna fish?"