CAJUN ACCORDION DISCUSSION GROUP
When Steve plays it, it's definitely in Gm.
To my ear, it sounds rather modal, centering around G.
In order to play it in "Gm", you'd need a Bfl accordion.
If you're into Medieval Church Modes, this would be in the Aeolian mode.
If played it on a "C" accordion, it would come out in the key of "Am".
Clear as mud?