C 13sus4 on Banjo, and the Number That Writes It

C 13sus4 spells C – D – F – G – A – Bb. That much is fixed. What is not fixed is what it is CALLED: hand the same chord to a chart in A# and it is written 2; hand it to a chart in C and the identical chord is written 1, on a page nobody had to rewrite.

C answers to the 1, 2, 3, 4, 5, 6 and the 7 depending on what got called: it is a plain number in 7 of the twelve keys and needs an accidental in the other 5.

A banjo player reads a number as somewhere to be when the roll comes back around — the right hand keeps going through the bar line, so a chart change is a destination the left hand has to reach without the pattern stopping. The picking hand is committed a beat before the change, so the digit has to be converted while the previous one is still sounding.

Every shape below is drawn for GDGBD, 5 strings, open shapes first and movable ones after them, and each one plays back — because the fastest way to check that a number was read right is to hear it.