Chord Brightness Map (12 Major + 12 Minor)

For each triad root, estimate beating in fifth and third, then derive brightness and agitation scores.

Triad agitation model

\(A_{triad}=\alpha\,b_3+\beta\,b_5\)

Major vs minor interpretation

Major: calm → bright → ecstatic → manic.
Minor: grounded → wistful → urgent → haunted/intense.