(A bunch of it's AI generated. I guess when you've used practically every public domain song in existence you've gotta have an AI make the rest or something, idk at least it sounds good.)
Click on your phone in the game, then the music button. At the bottom of the music screen the track that's currently playing will be there, click on that, then the download button. It opens up a link to a MEGA folder with all of the game's music in it.