You have downloaded some M4A audio files.
You want to extract convert them to WAV files to listen to them in other devices that do not support playing M4A files.
- In the Music app on your Mac, choose Music > Preferences, then click Files.
- Copy the path of Music Media folder location. (An example path is Macintosh HD/Users/admin/Music/Music/Media.)
- Click the Import Settings… button.
- In the Import Using pop-up menu, set Import Using = Wav Encoder, then click OK to save the settings.
- Drag M4A files to the Music app.
- Select songs in your library, then click File > Convert > Create WAV Version.
- Go to your library folder (i.e. the Music Media folder location) and copy the WAV files to other devices.
- Delete the M4A files from your library.