The celestial spheres relate to Johannes Kepler's work Harmonia Mundi in which he drew together theories from the world of music, architecture, planetary motion and astronomy and linked them together to form an idea of a harmony and cohesion underlying all world phenomena and ruled by a divine force.

Although this work remained untranslated into English for over 400 years, finally astronomer and mathematician Dr J. Field translated the Latin into English for publication by the American Philosophical Society in Philadelphia:

Aiton, E. J., A. M. Duncan, and J. V. Field The Harmony of the World by Johannes Kepler Memoir 209 (1997)

The earlier French and German translations were of poor quality and incomplete.