Apple’s iPhone will not allow you to set a song that you didn’t legally obtain through iTunes as your ringtone.
I mean, you’re not supposed to download music illegally, after all, right? Well, in a word, yes — thats a given. However, Apple carried the torch a bit too far this time around, because, in addition to that restriction, you also aren’t allowed to use songs that were downloaded legally and synced via iTunes to your iPhone’s music library.
Fortunately, there exists a way to work around this; and no, you don’t have to jailbreak your device or do anything illegal, either. You need only to obtain a licensed copy of Apple’s GarageBand app for iOS, which, ironically enough, is free to download on devices shipped with iOS 8 or later, and costs just $5 otherwise. Once GarageBand is installed on your iPhone, you’ll only need to run the song through the app to turn it into a ringtone by following the procedure below as outlined by Osas Obaizamomwan from iPhone Hacks.
Start by importing the desired song to your iTunes music library. You can download the song on your iPhone, directly from the iTunes app, or, if you’re using a desktop computer, simply drag the song into your iTunes library and sync it to your iPhone.
1. Open GarageBand on your iPhone, if you haven’t done so already. Keep in mind, though, it’s a big app — storage wise — at a whopping 630MB.
2. Next, import the song into GarageBand as a “New Instrument Track,” by selecting an instrument > selecting the app’s “View button,” > and finally, selecting the “Loop Browser button.”
3. Select the “Music Tab” from the Loop browser, and then search for the song from any of the sub-sections. Unfortunately, keep in mind, certain songs — those not stored locally on your iPhone —can’t be imported and converted to ringtones.
6. Finally, by tapping on the thumbnail for your song, a window displaying several different options will appear. Tap the “Share” icon > the “Ringtone” icon > then name the file and select “Export.” Select “Use sound as” > and then select the kind of ringtone you want this to be.