A little bit of background. I was one of those who jumped on the inaugural Google Play Music (GPM in short for the rest of this post) subscription plan, because they promised an $8/month lifetime fee. At the time, apart from the price, it has some other advantages over the other services: you could upload your own music and have a unified music library [Amazon’s two-library thing with Prime-Music and your-own-music was annoying], YouTube RED was included, you could watch YouTube proper without ads, and you could play YouTube on your Android phone in the background…
But GPM had a dark secret and that secret was revealed to you AFTER you cancelled the for-pay service. Your playlists got emptied out of all music except for the songs you owned or you uploaded. So if you were using the playlists as precious music data, you were SOL!
I got lucky because after I cancelled, I had one un-synced airplane-mode old phone that had the playlists, so I took screenshots of them. But most people were not as lucky…
As you can see above, all but two songs remained in this music playlist (as the title hints at, this was a playlist with headphone testing test-track candidates)…
So it was goodbye playlists…
… UNTIL the Big Silver Lining. Google is phasing out GPM and you have the option to transfer GPM to YouTube Music. With GPM, you can only listen to music you own (unless you are a monthly subscriber). With YouTube Music you can listen to whatever’s available, with the caveat that music you don’t own/upload will have Ads on it and you can’t play it in the background on an Android phone…
Because of this, when you transfer your old GPM playlists to YouTube Music playlists they will get re-populated with all the music ~ as long as that music is available at YouTube Music as well. Because these are two different services and their contracts were signed at different times, there might be some discrepancies, but the vast majority of music should be in common…
So now, with access to the ad-based YouTube Music library (in addition to my own-and-uploaded music), my “Test Candi” playlist is alive again with 22 test tracks!