Sorry for the oversimplification. As one who read Sylvia Wright's original in Harpers Magazine in the 50s, and subsequently in her book "Get Away From Me With Those Christmas Gifts!", I do appreciate the fine points of what is and is not a mondegreen ... but was indulging in shorthand to get a point across.

To be proper about it, you might call a mondegreen an "unwitting pun." Usually not a single word, but a mishearing of a short phrase, more or less serendipitous.

Of course far too many people, knowing full well what they were doing, have have forced the mishearing process, using pun mechanisms to come up with intentional mondegreen phrases; and that has blurred the distinction for most who today have no idea where the original mondegreens came from. But yes, the "purest-of-the-pure" mondegreens (some of Wright's, but not all, e.g.) are inadvertent.

All of which obscures the point I was making above.

Perhaps what is needed, puristically speaking, is to put the 13 June 8:34 am ballad through a low-powered speaker and, fortuitously, misunderstand it line by line, in order to make it into a mondegreen ballad.

Not my bag of tricks. But someone ought to try.