For a standard 5-string banjo, there are two ways to get around the key restriction: capos and retuning.
As I mentioned in “Let’s Capo,” it takes two capos to change the key of the whole banjo: a banjo capo to cover strings 1-4, and a 5th string capo.
A variety of 5th string capos are on the market. Some are permanent rails holding moveable fretting “fingers”; others are small gadgets temporarily attached to the banjo at the chosen pitch.
Another possibility is to drill the fingerboard and insert “railroad spikes” along the 5th string. You hook the string under the head of the tiny spike to capo the string. Banjo players find this more convenient than it sounds. But it’s a delicate operation to place a spike correctly; do not attempt this at home!
An interesting thing happens if you capo all 5 strings at the 5th fret or higher: The 5th string sounds the same note as the 1st string.
None of these complications apply to the capo-ble banjo, of course.
Next post: retuning.