The red haired banjoist was certainly none other than the woman affectionately known as "Futile" Tuning. The "Dumdedum Diddly Song" Greg Stephens mentioned above is her trademark tune. I haven't seen her for a while although I'm told "The Barroom Floor" is a likely venue where she may be seen. To the best of my recollection, the chorus was something close to:

Diddle di dee dum
Diddle dee di day
Doodle diddle, doodle doo
Dumdedum Diddly dit

Sorry, that's all I can dredge up from my deteriorating memory.