Ganey and I just recently had a similar discussion about this song. He has the answers - I just tap my foot and try to play the tune.

In the Balfa Brothers fiddle version, it is played in G major. The chords are G, Bb and D. In the accordion version, it is in Am. The chords being Am, C and G. The Mamou Playboys blended the two songs by starting off the fiddle version in G, then coming in at the end on the accordion in G minor using a Bb accordion.

Yes, it's that kind of "floating" between major and minor that makes this kind of old music so exciting, just like pre-war blues. Good stuff!

Thanks to all for the help.
Any other suggestions on how to play Mardi Gras Dance other than the Balfa version?
JB

There seem to be many more versions of this song than the famous Balfa rendition.
Lots of different melodies, chords, major, minor, you name it. Website #1.

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