by When is an MP3 not an MP3? When it’s a PDF. This isn’t the Mad Hatter in Alice in Wonderland, but a sort of question posed by Apple’s Music app in macOS. One reader and some other people in forums have encountered a seemingly rare issue in which the file types used for music and music video files become corrupted in the Music app’s library database. Instead of appearing as MP3, AAC, or other formats, they appear as PDF or even stranger file types.
Despite that oddity, Music will continue to play the files just fine. But when you try to export the file and use it elsewhere, it shows up as an invalid format. Is there a way to fix this? Yes, but it’s a slight pain. Apple doesn’t offer an option to rebuild your Music Library as the company does for the Photos Library.
There’s a series of steps you can follow.
Warning: You may lose playlists, counts, custom data, skipped tracks, and other data depending on how you’ve set things up. This isn’t quite a last resort, but it does solve the specific problem and introduce seemingly lesser but significant other ones.
Our reader who had this issue confirmed the following worked for him:
First: Create a full backup of your Music Library. This may be as easy as quitting the Music app, navigating to Users > Account Name > Music, and copying the Music folder to another folder (Option-drag) or another volume with enough space. (If you have an iTunes migrated library or store your files elsewhere, go to Music > Preferences/Settings > Files to find your library folder.)
However, if you are using what Apple formerly called iCloud Music Library (and still does under Windows) and now calls Sync Library, you may want to be sure you have a full local download before proceeding. These instructions will help.
Second: Move the original music files’ folder out of your Music Library folder. Depending on whether you have a legacy iTunes Music folder or just a new Music one, it could be named in different ways in Users > Account Name > Music (or wherever you store your library, as explained above):
- Music > Media
- iTunes > iTunes Music
Third: Launch Music. It will create a new music folder. It should retain your playlists and other information and may display errors about missing files. Now:
- In Music > Preferences/Settings > Files ensure that “Copy files to Music Media folder when adding to library” is checked. You want all your music files to be back in the music file with Music handling the process.
- Choose File > Import and select the music folder you moved out of the Music Library. Import may take a while.
- When complete, check that your library as it appears within Music looks correct and the file types are correct when copied or exported.
- Now you can delete the music folder you previously moved out of the Music Library or other folder. Retain your backup in case you discover missing files later.
This Mac 911 article is in response to a question submitted by Macworld reader Peter.
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