Did you know that Will Smith and Jimmy Fallon's grandfathers were in a jazz duo and had a radio show together in the 1920s?

That was the premise of a sketch the duo did during Smith's appearance on 'Late Night With Jimmy Fallon.'

Recently "found" footage showed the two "grandfathers" performing songs that sound suspiciously like Will Smith hits from the '90s. Check it out.

We have to say, the ragtime version of 'Parents Just Don't Understand' is far superior to the one released in 1988. And now we know there is yet another musical genre that Jimmy Fallon can masterfully channel.

But things do get a bit weird when the "grandfathers" sing a tune specific to Will Smith's upcoming film 'Men in Black 3.' How in the name of time and space did that happen?

Speaking of upcoming movies, we think Fallon and Smith's version of 'Gettin' Jiggy Wit It' would sound perfect in 'The Great Gatsby.'

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