Google has rolled out new version of the Google Play Music and is now throttled to the V5.8.1809. The update appears to be pretty minor and may only be UI tweaks.
The first big tweak we see is the addition of the full-height navigation drawer. Along with that there’s a general design tweaks, the artist, genre, and album pages have gotten a bit of a redesign, and you’ll also find a change in the look of the slide-in drawer on the left of the app.
Currently the update is not present on the Play Store but you can download it from here and can sideload it to see the changes and enjoy them.