How to set any song as iPhone ringtone without using iTunes
Step 1. Download or import the song that you wish to be your ringtone into your Music Library. If you skip this step you will not be able to find the song within GarageBand.
Step 2. Open GarageBand. If you do not have GarageBand pre-installed on your device, you can download it in the App Store.
Step 3. Import the song you want by choosing any of the instrument sections and tapping on the View button followed by the Loop Browser button.
Step 4. Next, select the Music tab and find the song you want from any of the sections. Songs that are grayed out cannot be added to GarageBand.kilde