Eeeee-ha! I've played this Cajun tune with David Lange, Melanie Solanen, and Chris Anderson plenty of times at the Thursday night Coop Jam. Like a lot of the tunes Dave brings, it's got that lonnnnnng melody line that just doesn't want to turn that chord corner... and then WHAM, it does. The tune is linked to SoundCloud where much of our music has to be stored, and the sheet's downloadable. It's in G, no problemo for us guitarists.
https://soundcloud.com/riskykayray/back-door