How can I transfer music from my Windows PC to my iPhone now that iTunes is discontinued?

Apple Devices is the replacement for managing the phone, so the iPhone not appearing in iTunes is expected now. Pressing Sync by itself may not add anything unless the music library has first been imported into the newer Apple Music app and the appropriate sync settings are enabled. Check that the songs are present in Apple Music, then connect the phone, choose its music settings in Apple Devices, select what you want to sync, and apply the changes.

The current Windows setup separates iTunes' old features between Apple Devices, Apple Music, and Apple TV. Apple Devices handles the iPhone connection and syncing, while Apple Music manages the music library. Install the required Apple apps, open Apple Music, and import your existing iTunes library from the Documents folder if it does not appear automatically. Then use Apple Devices to select the music-sync options and apply the changes. It is also a good idea to uninstall iTunes afterward so the phone is not trying to communicate through the outdated app; removing iTunes should not delete your media library.

If you do not want to use Apple's replacement apps, another option is a music-transfer app that runs on both the computer and the iPhone. These can transfer files wirelessly and avoid the old iTunes workflow, though they may not reproduce every playlist, rating, or library feature.