I first heard this song many, many years ago, and it astounded me then, as now.
The song inspired by a supposedly true incident that had happened 150 years earlier, was written in 1947 and has been performed by a great many singers.
Ray Steven’s version is my favorite, if for no other reason than the rising panic in his voice as he explains the process that lead to this odd, but completely legal conundrum.
I was lucky enough to find a version of this that includes a diagram which will make the whole thing perfectly clear to you.
I give you, Ray Stevens and “I’m My Own Grandpa”.