Piano Ensmeble of NTU

I was asked to help my friend to take a few shots for Piano Ensemble in NTU. We decided to take photos in Nanyang Auditorium. I chose to use 10-20, 30 and 85 with a 420 flash. 
I took the photos in about 1 hour, then processed them briefly. There were a few things I feel quite challenging; I found it difficult to include both the player and piano in the frame, while at the same time show the face of the player. I guess it's easiest to show the side face of a player, but it's certainly not ideal if everyone shows only side face...
Another problem is how to pose 30 people, one by one, with different gestures; and you have to make the balance so that there is a spontaneous feel and the gestures don't look too rigid. Well, sometimes you have to capture the movements of players, and I really hoped I have a camera with better high ISO performance.
In the end, I found I used 10-20 most often, 30 sometimes to shoot half body, and 85 only a few times to take head shoulder shots. I used RAW for the white balance is much easier to adjust. Here are a few shots from the shooting