Update...
Thanks Seeker. I got it, installed it and ran it. It told me that everything in my Music Library is in a playlist. No apparent orphans. But here's what I'm having problems with. There are many instances where I have multiple duplicates of songs (same with videos too). I don't mean 'live cut' vs. 'studio' dupes, or same song, different albums/lengths: I mean multiple copies (two or three) of the SAME THING. I don't know how THAT happened, but it did. So obviously I want to eliminate the dead weight and save disk space. But I don't know WHICH of the two or three copies is the one attached to the playlist, and which are just superfluous copies I can ditch. So I need a way to indentify them. Is there anything in iTunes or otherwise that will do THAT? Any possibility such a feature may get added by Apple or a third party? If you could search for 'duplicates' (as you can now), but then the resulting list would ALSO show which songs are ACTIVELY attached to playlists, it would enable you to safely discard the unattached extras. What do you think?