List Break - Queen's Choir

This is a quick thing I've always wondered about. Everyone here likes Queen right? Yeah, well after listening to We Are The Champions for like the millionth time, I noticed something. They have a really overproduced-Meat Loaf like sound to them, we all know that, but there's something I can't get around. What's with that opera that seems to be on every album. You can really hear it in the opera section of Bohemian Rhapsody. How do they do that? I know it's a bunch of over laid vocal parts but how do they do that. And how do they do it live then? Just thinking about that.