Have updated my MacBook to the latest HighSierra IOS software and iTunes to the latest version under High Sierra. iPhone X up to date with latest software. iPhone has downloaded purchased songs. Won't sync songs in the library onto the phone.
See Sync your iPhone, iPad, or iPod using iTunes on your computer - Apple Support. Check your sync selections. Do you have either Apple Music or iTunes Match? If so you would normally enable iCloud Music Library.
tt2
See Sync your iPhone, iPad, or iPod using iTunes on your computer - Apple Support. Check your sync selections. Do you have either Apple Music or iTunes Match? If so you would normally enable iCloud Music Library.
tt2
itunes won't sync music library with iPhone
