Picture Puzzle from Prolight + Sound 2013

Prolight + Sound team browsed its virtual photo album and found a wonderful picture reminding them of Prolight + Sound 2013. Naturally, we don’t want to keep it from you. However, we are not going to make it too easy. Using Photoshop we played with the control knobs, picked a small cut out and saved it as a new picture. Can you figure out which stand the picture is from and what is going on? We look forward to your comments!