Echoes of Aetheria

[Poutlaw]

I know this is an older game and I am replaying it . In chapter 30 I am about to pull my hair out. She is dancing but I cant get her to explode the crystals on the stage. I have even looked at a video of the sequence on YOU TUBE and I still cant make her do anything. HELP please. What the heck am I doing wrong?

Thanks