My music will not play

Hi, try to force reboot your phone - Force restart iPhone - Apple Support

Not sure why convenient features get removed with every OS 'upgrade'. The latest seems to be my iPhone will no longer play it's music on my desktop (when connected via cord to the computer, I could play music loaded onto my phone (my own music, not purchased, not downloaded, not rights-protected, not streamed; loaded onto my phone) through my desktop speakers. This no longer works. Doubtful has something to do with Apple IDs, though I don't want to log into my work computer using my personal Apple ID, nor do I wish to use my work Apple ID on my phone.

Keep looking for a workaround or something; iCloud sharing, family sharing, authorizing computers... it's all getting a little ridiculous Apple.

You need to start you own post so that more people can see your issue.