I play the piano, and I don't know why, but recently, every time someone walks in the room while I am practicing, I get nervous and start making a bunch of mistakes. Like, I have songs that I can play perfectly when I'm by myself, but when I play for someone, or someone walks in the room, I make mistakes, and do terrible! How can I get over this? It really is a stumbling block for me, because we always have people who want to hear me on the piano. Please help!