Why can't I use Apple Music to convert an M4A file to AAC?

Hi,

If you look in you library, select get info on a track and you will see file type - it should include AAC audio file in its description.

M4a are AAC will play. Note M4a is also used for Apples lossless format ALAC.

Jm

Hi,

Why are you trying to convert M4a to AAC when the format of M4a is already AAC? All you are achieving is lower quality version of the original track!

Jim

If you navigate to the new copy in Finder and press Command-I, what kind of file does it say it is?

You might try rebooting in Safe Mode.

Start up your Mac in safe mode - Apple Support

Note that Safe Mode is a troubeshooting too. Everything will run more slowly. Test in Safe Mode and then reboot normally.

Assuming that you are talking about purchased songs in AAC format, if the swimming headphones don't like the extension .M4A, you could just rename exported song files (not the ones in your Music Library) to have an .AAC extension.