Samsung Music Player

[CBvisitor]

How do I turn it off, or close the app, and keep it from running in the background?

Thanks 

[FrauHaseHH]

Does this work ...

Wipe down to get notifications, the music app will be there when its playing. Stop the Music. Swipe down again and the x button will appear to close it.
If there ist no x just swipe the app to the side

Then you can remove the player in the task manager

[ekieH]

To exit, swipe down from the top of the screen to display the music player. Choose the playback function you want to use. If you tap on the arrow, the menu opens completely. Tap the X icon to close the Samsung Music app.

Close app in background. Press and hold the app icon, then press i. select limited battery