Can't transfer music off of old iPhone
Last month I upgraded from iPhone 7 to XS. I had the 7 for a couple of years and got a new MacBook Pro during that time. I don't really use iTunes on my computer and I didn't notice that my music has never synced with it.
I did sign in to my iTunes account and this computer is authorized, but there are only ~300 songs in iTunes on my computer and there are 2600 songs on my phone. I've tried "transfer downloads" (the stuff not transferring is older music, most of it off of CDs), my old phone has been backed up to the cloud (but not the music?). I know there are apps I can pay for transfer this stuff (really don't wanna do that), but there has GOT to be a way to get this music back in my iTunes library, right?
The 7 isn't on iOS 12 because I'm afraid to update and lose all of my music.
Any ideas?
iPhone 7 Plus, iOS 12