If you have existing files in other formats (like CD rips) and want them in .m4a :
Since the iTunes Store primarily uses the extension for its music, downloading high-quality, DRM-free audio is a straightforward process. This guide covers how to set up your downloads for the best quality and how to manage those files once they're on your device. 1. Configure iTunes for M4A Downloads
Once your settings are correct, you can download your library:
Go to Edit > Preferences > General > Import Settings . Choose Encoder: Set "Import Using" to AAC Encoder .
Open the iTunes app and go to the Store or Library tab.
By default, iTunes downloads music in with an .m4a extension. You can ensure you're getting the best quality (typically 256 kbps ) by checking your preferences. On PC: Go to Edit > Preferences > Downloads . On Mac: Go to Music > Settings > Playback .
Tap the cloud icon to start the download. The file will be saved as an .m4a in your computer's "iTunes Media" folder. 3. Managing and Converting Files