The iTunes Store power search feature was useful. It allowed you to make multi-criteria searches of the iTunes Store. Over time, it went from a link on iTunes Store pages, to a secret URL, and Apple made some tweaks to the search results page last year.
But now, the iTunes Store power search is getting demoted. If you’re signed into Apple Music, it takes you to the New tab in iTunes, rather than to a store search. This is interesting; it suggests that Apple is really planning to push music rental to the detriment of music purchases.
If you don’t use Apple Music, then the iTunes Store power search link still takes you to the power search interface. (Or, you can search using an AppleScript.) But if you are signed into Apple Music, then you can’t use this power search any more to look for content in the iTunes Store.