Different audio files always feature with special formats that are compatible with authorized devices only. To play audio tracks on almost all popular players, the best way is to convert them to universal audio formats.
No matter what kind of audio files you collected, whether it's Apple Music or iTunes M4P songs, or Audible AA, AAX audiobook, or even normal audio file format like MP3, FLAC, WAV, OGG, AudFree Audio Converter for Windows and Mac would always be your best assistant.
It can completely convert a wide variety of audio tracks to popular file formats so that you can freely enjoy any music anywhere at anytime.
Compatibility:OS X 10.9 or later,
Homepage:

https://www.audfree.com