Currently, the only way to access Google Play Music on a desktop is via the browser. Strictly speaking, there isn't anything wrong with the browser version, but an official desktop is something that many users prefer over a browser tab. Now, with the eventual replacement of Google Play Music with YouTube Music, a desktop client is sorely needed, as a browser is often resource-heavy compared to the former.
However, there is an open-source, third-party app that attempts to mimic the functionality of a desktop app. The player has a lot of features that make it better than the web client, which you can take a look at below. It should serve as an adequate replacement until we see an official release from Google.
It is worth noting that the client is merely a wrapper for the services' websites, and the added features built into it could break should the sites be updated. It is still worth using, especially for Spotify users who are used to a dedicated desktop app for their music needs. It even has a LastFM integration for the prolific scrobblers out there. Other notable features include support for hotkeys which allow you to change tracks while in another application and a remote control service that you can use from your phone on the Google Play Store. Here's a complete list of features it offers.
- Media Keys support (Play, Pause, Stop, Previous, Next)
- Last.FM Scrobbling and Now Playing support!
- Desktop notifications on track change
- Simplistic mini player
- Customizable dark theme
- Taskbar media controls (media controls embedded into the taskbar) Windows only
- HTML5 audio support – No more Adobe Flash Player
- Built-in audio equalizer – Make it sound how you like it
- Background music playing, minimize to the taskbar
- Customizable hotkeys. No worries if you don’t have media keys – Choose your own shortcuts!
- Choose your audio output device from within the player
- Interface for external applications such as Rainmeter
If you want to give the Google Play Music desktop client a try, you can download it using this link.
News Source: XDA developers