App to play one song then stop

I am looking for an app that will play one song then stop playing. Doing a search for this only brings up complaints that Apple Music only plays one song. I’ve never had that issue but I want to be able to do this. Preferably I would like to download the songs into the app to keep them separate from my Apple Music. Before I get instructions on making playlists with just one song - I don’t want to have 200 separate playlists. I just want to choose a song, play it then stop playing and that the playing continues when the phone is locked. I had great success with this in the Goodreader app but that now crashes as soon as the phone locks so it doesn’t even play one song.