Music of the spheres
Musica universalis (lit. universal music, or music of the spheres) is an ancient philosophical concept that regards proportions in the movements of celestial bodies—the Sun, Moon, and planets—as a form of musica (the Medieval Latin name for music). This 'music' is not usually thought to be literally audible, but a harmonic and/or mathematical and/or religious concept. The idea continued to appeal to thinkers about music until the end of the Renaissance, influencing scholars of many kinds, including humanists.
The Music of the Spheres incorporates the metaphysical principle that mathematical relationships express qualities or ‘tones' of energy which manifest in numbers, visual angles, shapes and sounds – all connected within a pattern of proportion. Pythagoras first identified that the pitch of a musical note is in proportion to the length of the string that produces it, and that intervals between harmonious sound frequencies form simple numerical ratios. In a theory known as the Harmony of the Spheres, Pythagoras proposed that the Sun, Moon and planets all emit their own unique hum (orbital resonance) based on their orbital revolution, and that the quality of life on Earth reflects the tenor of celestial sounds which are physically imperceptible to the human ear. Subsequently, Plato described astronomy and music as "twinned" studies of sensual recognition: astronomy for the eyes, music for the ears, and both requiring knowledge of numerical proportions.
Later philosophers retained the close association between astronomy, optics, music and astrology, including Ptolemy, who wrote influential texts on all these topics. Alkindi, in the 9th century, developed Ptolemy's ideas in De Aspectibus which explores many points of relevance to astrology and the use of planetary aspects.
In the 17th century, Johannes Kepler, also influenced by arguments in Ptolemy’s Tetrabiblos, Optics and Harmonica, compiled his Harmonices Mundi ('Harmony of the World'), which presented his own analysis of optical perceptions, geometrical shapes, musical consonances and planetary harmonies. According to Kepler, the connection between geometry (and sacred geometry), cosmology, astrology, harmonics, and music is through musica universalis. Kepler regarded this text as the most important work of his career, and the fifth part, concerning the role of planetary harmony in creation, the crown of it. His premise was that, as an integral part of Universal Law, mathematical harmony is the key that binds all parts together: one theoretical proposition from his work introduced the minor planetary aspects and harmonics into astrology; another introduced Kepler’s third law of planetary motion into astronomy.
The three branches of the Medieval concept of musica were presented by Boethius in his book De Musica:
- musica universalis (sometimes referred to as musica mundana)
- musica humana (the internal music of the human body)
- musica instrumentalis (sounds made by singers and instrumentalists)