Even if someone will come and say that they have been inspired to teshuva, somehow, by selichos concerts, there are limits; ths Torah isn’t hefker, and playing instruments while we bemoan out state of distance from Hashem in sinfulness, simply shows that the people involved do not even know the translation of what they’re saying.
Inspiration is important, but temporary…ask these same people how the coming year was, or even how their yom kippur was…if they’re being honest, they’ll probably say they had their typical boring yom kippur and fell asleep during davening.
A great cause of boredom and the feeling of a need to innovate comes from simply not knowing what they’re saying when they’re forced since childhood to sit in shul and spout random Hebrew words that are difficult to read because they’re not in the everyday siddur, which they also find boring because no one ever bothered to teach them what they are actually saying.