In Windows, Microsoft's own Groove Music is the default music player app when you first start using it. But, while it's not a bad app, music players are pretty personal and everyone has their own preferences.
So, if you'd rather Groove wasn't the default player follow these steps
- Open Settings and click on Apps
- Select Default apps from the left-hand pane. Scroll down until you see Music Player
- Choose your alternative or find one at the play store.
You'll see Groove Music is selected currently, and this is what you want to change. Click on the box and you'll be presented with a list of apps you have installed that are suitable for this category. Simply select your favourite and it will now become the default music player whenever you're using Windows 10.