This articule weird because it's holding the anthems to a standard that doesn't make much sense. In traditional music and hymns, tunes and words are semi-indep

This articule weird because it's holding the anthems to a standard that doesn't make much sense. In traditional music and hymns, tunes and words are semi-independent, and it is completely routine for one tune to have multiple sets of words set to it, or one set of words to have multiple tunes. If you claimed you wrote the tune when you borrowed it, sure, that's plagiarism. But setting words to an existing tune while acknowledging that you are doing so is perfectly okay.