Hello, I've seen similar Ideas, but not quite as explicit as mine. I'd be surprised if the desktop client doesn't employ a regexp search in the background, once something is searched for. If so, why not extend that into the user interface?
That would solve any and all filtering questions, for those inclined to use it in that way, and wouldn't have to be anything to tout much since many might not care, but a silent availability would be nice.
The above, with the added twist of having keywords for including the metadata in the search would nice, i.e, record label, year and so on, provided it's available in the first place.