Hi Bob,

Eddie Condon used the plectrum tuning for his tenor guitar. CGBD.
Marty Grosz does something like this. He tunes his top four guitar strings like a plectrum and his bottom strings in fifths. BbFCGBD. Apparently this was the tuning for the guitarist Carl Kress in the late twenties and early thirties in his duets with Dick McDonough.

Martin, the four-string banjo community is very active. Chuck Ogsbury of Ome Banjoes has been making a state-of-the-art tenor and plectrum banjo. They are not gathering dust if they are any good.
I own a Bacon and Day #1 from 1922 which I play occasionally when I'm not playing my Ome. Vega Voxs and Paramounts are also popular amoung 4-string players but they don't have the punch that the B and D's or the Omes have.

It is true, however, that since Earl Scruggs, the 5-stringer has overtaken the 4 in popularity but there are still plenty of good 4-string players around today. They don't travel in folk circles.

Most of the traditional five-string players such as the Round Peak style players do fret the fifth string occasionally. This gives them a little more freedom to select the notes that match the fiddler.
When you get into fifth string capoes, then you don't have this flexibility as much unless you tune the banjo to standard open string tunings without the fifth string being capoed.


Frank Hamilton