I agree with Pegasus on this. When I read your post I immediately thought of PTSD flashes. There is something related to the music that is supressed and T needs to know what is going on so you two can explore it in a safe place and safe way. I am sorry this is happening. It is difficult. It sounds like it is just under the surface. Good luck and much support....
A trigger can be anything and come at any time....it is hard, especially when it blind-sides you.