Any offline music player app on apple?

If you have a subscription to Apple Music, you can download a phone full and play it offline. I think it’s $10 per month but you might get a free trial - I did once.

The only PORTABLE off-line music player I have is this. It's a portable cassette player with a built-in AM/FM radio. When it comes to music players, you can't get more off-line than that.

Yes but how would you get music content into your phone?! If you use Apple Music it’s $10/month. 3rd party apps just give you the music player, no content.