Idea for a painting background?

I have a very large canvas, four feet by three feet. I wanted to paint five dancers, but I'm unsure about the background. Originally I planned for a plain colored one, but that's boring to me. Then I thought that having them in a city alley of sorts, then it would be visually interesting or ironic, and I could even sign my name in graffiti on the wall. But when I sketched the idea, it just looks confusing. Any suggestions?