If you’ve got many songs in Google Play Music, it can be difficult to manage which songs are in which playlists. Google Play Music doesn’t show you a list of playlists a particular song is in, if any. To create such a list, here’s a solution that works.
The result will be a JSON file containing a list of songs where for each song there will be an array of playlists the song is in, e.g.
"Madonna - Santa Baby": [ "Christmas" ], "Madonna - True Blue": ,
In the excerpt above, we see that the song “Santa Baby” is in the Christmas playlist but the song “True Blue” is not in any playlist. You can then find a playlist to the the latter song in so you don’t forget that you have that song.