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.
 Esoteric Christianity
- musica mundana (sometimes referred to as musica universalis)
- musica humana (the internal music of the human body)
- musica quae in quibusdam constituta est instrumentis (sounds made by singers and instrumentalists)
According to Max Heindel's Rosicrucian writings, the heavenly "music of the spheres" is heard in the Region of Concrete Thought, the lower region of the mental plane, which is an ocean of harmony.
 See also
- Weiss and Taruskin (2008) p.3.
- Pliny the Elder (77) pp.277-8, (II.xviii.xx): "…occasionally Pythagoras draws on the theory of music, and designates the distance between the Earth and the Moon as a whole tone, that between the Moon and Mercury as a semitone, .... the seven tones thus producing the so-called diapason, i.e. a universal harmony".
- Houlding (2000) p.28: “The doctrine of the Pythagoreans was a combination of science and mysticism… Like Anaximenes they viewed the Universe as one integrated, living organism, surrounded by Divine Air (or more literally ‘Breath’), which permeates and animates the whole cosmos and filters through to individual creatures… By partaking of the core essence of the Universe, the individual is said to act as a microcosm in which all the laws in the macrocosm of the Universe are at work”.
- Davis (1901) p.252. Plato’s Republic VII.XII reads: “As the eyes, said I, seem formed for studying astronomy, so do the ears seem formed for harmonious motions: and these seem to be twin sciences to one another, as also the Pythagoreans say”.
- Boethius, De institutione musica, I.2 (p. 187 Friedlein ed.)
- Davis, Henry, 1901. The Republic The Statesman of Plato. London: M. W. Dunne 1901; Nabu Press reprint, 2010. ISBN 978-1-146-97972-6.
- Hackett, Jeremiah, 1997. Roger Bacon and the sciences: commemorative essays. Brill. ISBN 978-90-04-10015-2.
- Kepler, Johannes, 1619. The Harmony of the World, translated by E.J. Aiton, A.M. Duncan and J.V. Field (1997). Philadelphia: American Philosophical Society. ISBN 0-87169-209-0.
- Pliny the Elder, 77AD. Natural History, books I-II, translated by H. Rackham (1938). Harvard University Press. ISBN 0-674-99364-0.
- Smith, Mark A., 2006. Ptolemy's theory of visual perception: an English translation of the Optics. Philadelphia: American Philosophical Society. ISBN 978-0-87169-862-9.
- Soanes, Catherine, (ed.) 2006. The Oxford Dictionary of English 2nd ed. Oxford University Press: Oxford. ISBN 3-411-02144-6.
- Weiss, Piero and Taruskin, Richard, 2008. Music in the Western World: a history in documents. Cengage Learning. ISBN 978-0-534-58599-0.
 Further reading
- Calter, Paul. "Pythagoras & Music of the Spheres". Geometry in Art & Architecture. Dartmouth College. Retrieved November 26, 2011.
- Plant, David. "Johannes Kepler & the Music of the Spheres". Skyscript.co.uk. Retrieved November 26, 2011.