I've experienced that a lot. Most recently quite by accident I saw a 1935 movie, ROBERTA, starring Irene Dunne. She sand in the move quite beautifully and I wanted to know if it was in fact HER voice.
It was. I don't know if she ever made any other movies in which she sang but that was a first for me.
It was a nice surprise.
What if anything nicely surprised you recently?