The "classical" banjo refers simply to the style or type of banjo playing, not the playing of "classical" music on it. Any sort of music can be played in "banjo classical" style, and it usually means a fretted 5-string or a "Cammeyer" zither-banjo . This is the instrument on which Clive Palmer learned and I've never heard him do "classical" music in the sense being suggested above, though these banjo players do take it very, very seriously indeed!