I feel like the color scheme doesn't work. You are using two primary colors (blue & red) which are both dark along with black and white. My personal opinion is that you should try to add a lighter color, or lighter shades of the colors you are already using to brighten the mood. The darkness in this picture brings down the overall tone.
Answer: It was the show that completely changed the way musical theatre is staged. Oklahoma was a first and it has remained one of the greats since it burst onto Broadway in middle of WW2.