These symbols are fussier than necessary, because they are trying to be cute about both the mapping to the alphabetic scale and slavishly sticking with circles.

These symbols are fussier than necessary, because they are trying to be cute about both the mapping to the alphabetic scale and slavishly sticking with circles. What is required is a sequence of length seven (for convenience) that allows sharp/flat prefixes and time length suffixes. Circles are merely one option. If written by hand, there will be ambiguities between C, Dot, Empty, and Full. I think a graphic design artist had too much fun with this project...