"in my opinion" is implied here, especially given the context of the surrounding discussion.

What I think your comment is missing is that the placebo effect is real even if it isn't useful in all cases. Music playing requires a large amount of mental activity across many centers of the brain as well as training and practice to improve muscle memory.

Double-blind trials aren't necessarily the gold standard when there are so many different variables across individuals that can't be controlled and the entire mental process for such a complex idea is not even close to being completely understood.