Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
The reason is, your musics are stored on iCloud and they have not downloaded to your iPhone yet. So go to Settings, tap Music and turn off iCloud Music Library. If it is off already, then turn it ON. Then turn it off.
Restart your phone. Then wait 3 minutes. Then go to Settings > Music and this time turn the iCloud Music Library back on. If asked to Merge or Delete, click Merge.
Please let me know if that didn't work, so we can continue troubleshooting
Do you see "Show Apple Music" ?
Turn it off. Then turn it back on
Now we have to redownload them.
Let me know once you did that
To make sure, you are using the same Apple ID (on this new iPhone) you used to purchase your music originally. Right ?
If you see Albums with cloud icon on the right side there, then tap it to download them.
If you don't see any albums, then open Music app and delete the greyed out or problem music albums (tap the 3 dots and tap Delete to delete them). Then goto iTunes Store > Purchased > Music and you should be able to redownload them from there by tapping the cloud button. Let me know how it goes
Open the Music app and delete the music or albums that have issues playing. Let me know once you did that
The reason is, only the titles are there and the actual music files are not downloaded from cloud. We have to delete them and redownload them.
On your iPhone, go to Settings > General > Storage & iCloud Usage. Now tap Manage Storage under STORAGE. You will see Music there. Tap it. Under MUSIC heading, swipe left with your finger on All Songs and you will see Delete button. Tap it and they will be deleted.
Then do the following