How to Use an iTunes Song as an iPhone Ringtoneby Paul Ramone ; Updated September 15, 2017
The iTunes application is well known for its music storing and playing abilities. It is essential when you need to sync your personal media files with an Apple product such as the iPhone or iPod. You can also use iTunes to create ringtones from songs within your music library. Properly create a ringtone and enjoy it on your Apple iPhone.
Open iTunes on your computer.
Select the "Music" category from the top left side of iTunes.
Right-click over a song that you want to turn into a ringtone and select "Create AAC Version." An AAC duplicate of the song will appear below the original.
Drag and drop the AAC version of the song onto your computer's desktop.
Edit the song on your computer's desktop by changing the extension from "M4a" to "M4r." This will allow iTunes to recognize the file as a ringtone.
Drag and drop the file from the desktop back into iTunes. The song will now be stored in the "Ringtones" category in the left side of iTunes. When you connect your iPhone to the computer, iTunes will sync the song as a ringtone.