I have a Google Play Music 'Unlimited' subscription. How do I make the songs in my playlist available offline, as you can do on Spotify and the Mobile Apps? I am not talking about just the 'Free and Purchased' songs, but all the tracks. Also, it needs to be legal. I don't do piracy.
It's not an option in the computer/browser version of Google Play Music. I've done this in the Android app. Find the content you want to sync offline, and tap the down-pointing arrow button.
In the Android app you can sync songs, albums, artists, and playlists for offline playback, limited only by the available space on your phone.