Here is the Pantheon in Rome: the lower diagram showing the building's main forms superimposed on each other. From Hay's The Natural Principles and Analogy of the Harmony of Form (1842).
Featured on PDR in the essay Music of the Squares: David Ramsay Hay and the Reinvention of Pythagorean Aesthetics
Understanding the same laws to apply to both visual and aural beauty, David Ramsay Hay thought it possible not only to analyse such visual wonders as the Parthenon in terms of music theory, but also to identify their corresponding musical harmonies and melodies. Carmel Raz on the Scottish artist’s original, idiosyncratic, and occasionally bewildering aesthetics.