As a country musician since my teens, I have been on a variety of stages performing and putting my whole heart into songs. I learned from a freind that I always looked miserable on stage. We concluded that I needed to smile more. So, he was at the next performance and during break said, "Dxmn, can't you at least smile inbetween the songs?" My reply was argumentative in that I thought I had been smiling. But the dim lights and my dark eyes make me look like a character from a Hollywood horror flick. So, I figured it out. If I place my top teeth on my bottom lip, from anywhere in the room I look like I am smiling and happy. I have tried this when I was not very happy about a situation and no one suspected that I was miserable or ready to chew nails. The neet thing is that if you are in the proximity of a microphone, no one has to hear you humming.
Just a thought to pass on. I've watched performers and they are so serious about their performance that it would seem they have no joy in it. It is rare I see them delight in the fact that they have an audience.