How to lock screen when playing music?

[AC Question]

(HTC one m7) When playing music I can't lock the screen. If I try to back out or hit the power button which normally lock it, the music stops playing.

(When I put music and video files in the phone, I put them into the music folder on device memory, and access them for playback through the media gallery)

 

[Miller6386]

Use a 3rd party music player like rocket player or something

Note 4Tified