"Hey, who wrote the piano concerto that goes like (hums a few bars)? I want to say Rachmaninoff, but I'm not sure."*
"Could be Schumann, they're pretty similar."
"Are you kidding? Not if you've actually played the piano parts!"
"Okay, but they sound pretty much the same."
(sotto voce) "Maybe to a cellist..."
* Turned out to be Grieg's A Minor concerto. Boy, was I off!