Big Mon is easily one of the coolest Bluegrass tunes every written, and of course, it was written by Bill Monroe on his Gibson F5 Mandolin, and that, of course, is the source of the name. I've no idea if Monroe would have named it that himself and for himself, but more than likely, someone else called it that - and it stuck.
Big Mon is not truly a complicated tune to learn - like all Bluegrass tunes, it can be made as simple or complex as you wish to make it, but what it is is something meant to be played VERY fast, and because of the herky jerky melody, it's just really a head bobbing, and funky masterpiece of a song.
Now Big Mon is a bit different in it's history as this song was written by a mandolin player for the mandolin,...