Just an item to consider -- given the very low cost of storage these days I'm not sure why anyone would put much effort into deleting duplicate music files. I have the odd track here and there that is in more than one spot (i.e., on the original release and then a greatest hits release or a "mix tape" of my own creation, etc.) In fact, in some situations removing the file would render an album less enjoyable. So, not anything I'm going to worry about.