Interesting questions, all. Since banjos are played in so many different tunings, the whole question of "correct or standard tuning" is somewhat cloudy. Pete often has his wonderful tubaphone with the rosewood long neck tuned in C tuning with strings 1-4 tuned down 3 half-steps and the 5th string to G. That would be A, E, G#, B, G. He then capos strings 1-4 at the 3rd fret for standard C. This makes the keys of A, Bb and B available to him by moving or removing the capo and tuning his 5th string down.