1. Take the oppoR11 mobile phone as an example. Light up the mobile phone desktop, find the "File Management" selected in the red box, and click to proceed to the next step.

2. Find the "Internal Storage" selected in the red box and click to proceed to the next step.

3. Enter the internal storage homepage and slide down to find the music folder.

4. Find the "MUSIC" folder selected in the red box and click to proceed to the next step.

5. The song file selected in the red box is the song file.