I bought songs from iTunes for my husband and then discovered that when I copied them onto my mp3 player the format was wrong and they wouldn’t play.
Apple doesn’t really want their music to be played on music players other than the ones they sell, so they don’t make it easy to change songs to mp3. The ones I downloaded were in MP4 format.
Go to EDIT in the top left corner of iTunes.
At the bottom of the drop down list choose PREFERENCES.
Open the GENERAL tap.
Click on the IMPORT PREFERENCES button.
Choose MP3 encoder next to Import Using.
If your songs are already in iTunes right click on them one at a time or highlight a group and right click.
From the drop down list it will now say CREATE MP3 VERSION.
This will create a second version of your song, in the same iTunes folder that is now in MP3 format and can be copied to your player.
I would assume that any song uploaded into iTunes could be changed to MP3.
But then again, it took me forever to figure this all out and I could be wrong about life in general.