Sure. A different search controller, which needs a different query view to handle the different fields it filters on, which needs a different result view to sur

Sure. A different search controller, which needs a different query view to handle the different fields it filters on, which needs a different result view to surface the different parts of metadata that only apply to this use case...you end up adding significant feature work to the app so that it can use the new search logic you "just" added to the backend, and you have still only solved one narrow aspect of this surprisingly different use case. As I said before, I've spent a decade trying to solve this problem with the same kinds of approaches you're advocating here - that is, using tooling built for general music. That I haven't succeeded doesn't necessarily mean much, but how likely do you think it is that Apple's product and engineering teams didn't try the same before deciding they needed to ship a whole new app about it?