I'm the kind of person who can hear that stuff. If you sing along to the radio and you're not going to sing unison with the melody, but find the harmony, I find that pretty easy to do.
I just play to the people I can see. So it's almost like you are playing to the first few rows of the crowd. You can see the faces of the first hundred people, but then it becomes a blur as the crowds disappear over the hill.