I have many playlist on my Mac and iPhone. most of which I did not make, and are duplicates and triplicates etc. When I ty to delete them i get a message that they will be removed from my library, which I do not want to remove. TIA
I think you mean that you want to remove the extra playlists, but you don't want to delete the songs, just the playlist.
I am pretty sure that you need to empty the playlist (remove all songs from each playlist that you want to delete, then delete the now-empty playlist.
Here's what worked for me: select the playlist. click on one song in that playlist, then press Command-a. All songs should be selected. Right-click on the selected songs, then from the menu, choose "Remove from Playlist". Your song remains in the library, but the song is gone from that playlist.
Finally, select the playlist, and choose Delete from Library. It's now an empty playlist, and should simply disappear without any more "drama"
There may be some kind of third-party app that will clean up extra playlists, such as yours, more quickly than emptying each playlist manually. I've not ever looked for one. Perhaps someone else will respond with a method that will be faster than mine.
I think that when you add a song to your library, it goes "somewhere" (to a playlist, which iTunes creates automatically if none is selected), so if you don't want additional playlists created at that time, choose to add that new song to an existing playlist.