Q: I just upgraded to iTunes 18.104.22.168 and now some of my music files that I have backed up on my computer appear to be M4P files (and when I click on them they attempt to open in Quick Time as video) instead of MP3 files. How can I undo or change this??
A: The M4P extension refers to an AAC format audio track that was purchased from the iTunes Store. M4A is used by iTunes for standard AAC audio tracks, and M4P for iTunes purchased tracks.
In this case, the M4P extension is correct, and should be left as is—these files are not MP3 files, so they shouldn’t have an MP3 extension. Quicktime is the underlying playback engine used by iTunes itself, and is used to play both video and audio files. In this case, the problem is simply that your default association for these files is set to Quicktime rather than iTunes, in the same way that a TXT file is set to open in Notepad (Windows) or Textedit (Mac).
If you’re simply concerned about importing these files into iTunes, you can simply drag-and-drop them onto the iTunes window, or add them using the File, Add to Library menu option.
If you would like to re-associate this file extension so that you can double-click on these files and have them open in iTunes instead of Quicktime, you can do this through your operating system’s file association settings. This will be different depending upon whether you’re using Windows or Mac OS X.
If you’re using Windows, simply go to the Tools, Folder Options menu from any Windows Explorer window, and choose the “File Types” tab. Scroll down until you see the M4P extension, highlight it, and click the “Change” button:
You can then select iTunes as the preferred application for opening this type of file.
For Mac users, simply highlight the file and choose Get Info from the Finder menu.
From the file info dialog box, under “Open With” simply choose iTunes instead of Quicktime, and then click the “Change All” button to change this to be the default for all files of that type.