There's always the paid option of Deezer or Spotify, you can download music all over the place as long as you have a big enough SD card in your phone.
No idea what size is in my phone would need to open it up and check.
When i had spotify on pc the quality was not fantastic and later found you tube videos had much more punch giving me picture and better sound.
Also nearly every radio station has its own app so you can listen any show any time,also they have their podcasts in their too but you do need to use mobile data,Unless you drive behind a bus all the way to were your going for free wifi
I will only be on a few stations as have to scan them in, I would possible get murdered stalking Wheelo in his bus trying to get his wifey
🤣
You can download albums to your phone from pirate bay (you'll need a
vpn, and an app called uTorrent on your phone) or you can download them to a pc and copy them across to your phone the same way.
Not been on Pirate bay for many years and dont use vpn.
Also if you have amazon prime you can put the prime music app on your phone and download music from that, or just stream what you want.
I was looking at that when buying the radio and wondered how good the quality is on Prime?
Maybe another way is stick music onto usb stick,choices choices choices,possibly will be at destination before i chose what music to listen too.