It would be great if someone would post a slowed video for us to learn

I seem to recall the fabulous Chris Miller did just that in 2009. Here you are:

http://www.youtube.com/watch?v=htZeXzZkmug

Thanks for posting. Never saw or heard this one.
Another version with a different melody line, and in Am. (with a funny D chord at the end)
There are no "correct" basses to sustain the melody, and no guitar backing also, and still it sounds OK. Another great job by Chris!!

Here's a link to an MP3 of Nathan Abshire. I don't know where I got it, or the origin. Line #2 or http://www.nedcheever.com/mardi_gras_song.mp3