Harmonic Astrology

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An eighteenth-century engraving of the planetary spheres and the harmonies of the spheres, which relate to musical intervals. Reproduced by permission of Fortean Picture Library.

Harmonic Astrology

(religion, spiritualism, and occult)

Harmonic astrology is the term used for a system of astrological analysis developed by British astrologer John Addey in the 1960s and 1970s. Many of the concepts used in harmonic astrology have roots going back hundreds of years. Johannes Kepler developed a theory of aspects and planetary relationships that closely mirrors many of Addey’s ideas, and some of the varga charts used in Vedic astrology are equivalent to the harmonic charts used by Addey and other harmonic astrologers. However, Addey formulated many ideas that go beyond the scope of what had been developed before, and he supported his ideas with a great amount of research.

In harmonic astrology an aspect is viewed as a fraction of a circle. For example, a trine aspect of 120° is ⅓ of a circle, a square is ¼ of a circle, a sextile is 1/6 of a circle, a quincunx is, 5/12 and so on.

According to the theory of harmonic astrologer, aspects with the same denominator have a great deal in common. For example, a 1/7 aspect, a 2/7 aspect, and a 3/7 aspect have a similar meaning. The denominator is often referred to as the harmonic, so two planets that are in 1/7 aspect or 2/7 aspect, for example, can also be referred to as being in the seventh harmonic.

Another belief of harmonic astrologers is that doubling the denominator results in an aspect with a similar meaning. This theory is consonant with some beliefs in traditional astrology, such as, for example, that a trine aspect (ℵ aspect) has a similar meaning to a sextile aspect (1/6 aspect). Also, a ½ (opposition) and ¼ (square) aspect are hard aspects, and some astrologers also use the ⅛ (semisquare) and ⅜ aspect (sesquiquadrate) and also believe that these are hard aspects. Hard aspects are challenging and motivating. The ⅓ and 1/6 aspect, on the other hand, are harmonious and pleasant.

Harmonic astrologers believe that astrological aspects have much in common with sound waves. Interestingly, if a plucked guitar string is shortened to half its length, the resulting note is an octave higher. Musical notes that are an octave apart have a very similar musical quality even though the pitch of the two notes is very different. Similarly the sextile aspect is ½ the distance of a trine aspect and both aspects have a similar meeting. Similarly the ¼ and ½ aspects have similar meanings. These similarities between sound and astrological aspects incline harmonic astrologers to believe that waves similar to sound waves are the basis of astrological aspects. Harmonic astrology is not yet widely used, and there is not yet agreement on the meanings of different harmonics.

John Addey wrote several books that explain the theory and application of harmonic astrology in detail. Others have wirtten books in more recent times that have further developed and applied the concepts of harmonic astrology described by Addey.

—David Cochrane


Brau, Jean-Louis, Helen Weaver, and Allan Edmands. Larousse Encyclopedia of Astrology. New York: New American Library, 1980.
Harvey, Charles, and Michael Harding. Working with Astrology: The Psychology of Harmonics, Midpoints and Astro*Carto*Graphy. New York: Arkana, 1990.
The Astrology Book, Second Edition © 2003 Visible Ink Press®. All rights reserved.