I'm not sure that this fits within your parameters, but Uncle Dave Macon and Leroy Troy (and others, I'm sure), play(ed) banjo with only the left hand in many passages in pieces where they were ("are" in the case of Troy) spinning the banjo in various planes or gesturing with the right hand or holding the banjo out to swing as a pendulum in "My Grandfather's Clock". Admittedly, these are only fairly short passages, so presumably they don't meet your criteria.   Impressive, though, in context.

Dave Oesterreich