Thank you all. I have a go performing at a variety of events and venues. This recent one was a concert at an arts centre and it wasn't a folk evening; I had no control over the environment. I'll just have to imagine my audience members when I can't see them. The organiser of one of the other events (in the room with black walls etc) has decided she doesn't like the venue so we are changing to another. I have glaucoma and hate having to negotiate steps etc in darkened environments.