For the late Jim Hall—
Backstory: Icon, 1:44 PM ET today.
Update of 11 PM ET Dec. 10, 2013 —
For all the notes, see Da Capo (11 AM today)
and the Cullinane frequency matrix (12×12).
Matrix used to illustrate the well-tempered
scale. The integer frequency-ratio values
are only approximate in such a scale.