I've got a good one.
Imagine this... You're at a piano recital. The performer speaks a little before each piece. Something brief. Interesting little facts about the composer or piece. And then plays the piece.
Let's make that tidbit info incorrect. "Did you know Chopin was actually beginning to suffer from the effects of herpes, which eventually killed him, when he wrote this piece? That could explain the dissonances heard throughout the B section." *plays piece*
How many people would be sitting in the audience, catch an error like that, but have to sit quietly in the audience and say nothing because the performer is now playing the piece?
"This is an early piece by Bach, written his early teens, that he dedicated to Mozart." *begins playing right away*