Searching with symbols sometimes doesn't find any results, but because there are no files with those symbols. It simply doesn't find it. If you remove those symbols, results immediately start showing up.
Examples: Track titles with . or - symbols in them, feat. with a dot.
Solution: It might be a handy feature in settings, which allows a user to activate clear search feature. This means that when I copy/paste something into search, it will automatically remove all of the non alpha-numeric symbols as well as double spaces between words. This could also be implemented as a check-box inside the search field, which will activate this feature when turned on.