Good morning,
having struggled to find a quick and easy method to transform a song from the Music library into a ringtone, I offer you this method. I did a search on the forum and couldn't find anything better. Now, if my solution already exists on the forum and is redundant, I'm willing to delete the topic.
I have an iMac running Big Sur (11.5.2) and an iPhone running iOS 14.7.1
To put it simply, you can take a piece from the Music library. To do this, the file must be physically present on the Mac (if necessary, play the song in Music and click on "download". It can be found in Users/Account name/Music/Music/Multimedia/Music/artist name ).
Go to the file and duplicate it.
Right-click on the copy of the file and go to the "Quick Actions" menu, then "Shortcut".
Shorten the song by choosing a range of 30 seconds max by moving the two cursors.
Click on "Finish" at the top right, then on "Replace".
Rename the file with the extension "m4r" instead of "m4a".
Connect the iPhone to the Mac then in the Finder go to the iPhone "disk" then click on the "Music" tab (toolbar at the top).
Finally, simply drag the file in m4r format into the iPhone on the central area.
It's over ! The song is now recognized as a new iphone ringtone.
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