Well, a common mistranslation in song which sort of represents the folk process is in the Christmas carol, "Adeste, Fideles."
The phrase "laete triumphantes" should be translated--and originally WAS translated-- as "joyfully triumphant." (Check out some really old hymnals.) It evolved, of course, to "joyful and triumphant," and is nearly always printed that way today.
Genie