If you want to listen to songs while playing games, you can go to "bring your own music" APP > "mine in the lower right corner" on the "Settings" page in the upper right corner, and open the "Allow simultaneous playing with other applications" button, so you can listen to songs while playing games.

Tips:

The above path APPlies to the "Music" app that comes with the mobile phone. If you use a third-party music APP, you need to turn on the "Allow simultaneous playback with other apps" function in the "Settings" of the third-party music app.

This answer applies to all OPPO models.