Regarding the hyphen, he added it only when he is referred to as "Sir Lloyd-Webber" for fear that people would think his first name was Lloyd if it was not hyphenated. Except that he's a lord now, so it's Lord Lloyd-Webber. He's beyond a "sir."
As for his "masterpiece," I think he'll be remembered a century from now for "Phantom of the Opera," and it will be performed by major opera companies at that point.
My personal favorite is "Jesus Christ Superstar."
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22