I accidentally re-initialed the external hard drive containing my large Apple Music library and photos but have recovered most of the data. How do I re-add the music and photos so that the existing programs know where to find the data? Do I simply need to import and delete the duplicate entries created or is there a less labor intensive/more efficient method?
You do not need to manually import everything and delete duplicates. Both Apple Music and Apple Photos are designed to easily reconnect to existing libraries if you point the applications to the recovered files.
Try this
Quit the Music app completely if it is open (Cmd + Q).
Hold down the Option key on your keyboard and click the Music app icon to open it.
A window will pop up asking you to Choose Music Library. Click Choose Library....
Navigate to your external hard drive, locate your recovered Music Library file, and select it.
Update the Media Folder Location (if needed): If your music plays fine, you are done. If you see exclamation points next to songs, go to Music > Settings > Files (or Preferences), click Change..., and select the recovered folder where your actual audio files reside.
Re-add recovered Apple Music and Photos to libraries
