I also use this to play my music playlists on my phone. I use a button switch to turn the playlist on and another script to shut it off.
Only useful when I have the phone at home, but fun as all get out adding star trek sounds to events

Run playlist ->
adb shell am start -a android.intent.action.VIEW -d file:///storage/7AF6-191E/Roy-free-android/RFA.m3u
Shut it off
adb shell am force-stop org.videolan.vlc
I like having my phone play sounds, I will use it for when my solar powered batteries are full.