Banjo questions abound today!
About labels: Once someone asked Buell Kazee about what he called his style (he used the down-picking style labeled "frailing," "rapping," "clawhammer," "knocking" and many other things). Kazee reportedly answered, "I've been playing since I was about five years old, and I'm 60-some years old now, and as long as I can remember, we always called it 'Picking the banjo.'"
Country banjo tunings often have odd names or labels attached to them. Extra confusion comes from the keys used, since lots of those old-timers tuned the banjos up a tone to make the most common fiddle keys easier to match. So C tunings, of which the "2C" or "mountain C" tuning -- gCGCD -- is most common, would be "D tuning" if you asked. But there's a couple of "open D" tunings with considerably different intervals from that one (f#DF#AD & aDF#AD) that's also used. In Kentucky, what urbanites might call "F" tuning (fCFCD) is called "Old G" by some players, since it was tuned up to gDGDE. It was called "Old G" to differentiate it from "new G," gDGBD, the common bluegrass open G tuning.
So "sawmill" is "G modal" is gDGCD.
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