I thought I would post this because I finally managed to do something I have been wanting to do for three years. i'm not taking any credit because I managed to find all the information on the forum but not in one place.
I wanted to convert my playlists on Sonos which were pointed at Napster to Apple Music playlists. this also works for other services although there is another step to get to Amazon Music. This is for iOS but I am sure there is something similar for android.
Step 1: download an app called Phonos Plus. This will allow you to dump your track names from each playlist into a file readable by the web app below.
Go to Soundliz.com. This will allow you to import your file and import it to Apple Music, Napster, Spotify etc.
I'm not giving detailed instructions because both steps are fairly easy when you look around the apps.
you may lose a track or two on the way but you can see what they are and replace them directly.
probably takes five minutes per playlist.