1 The Emergence of Color Organs in the Eighteenth Century

In his Opticks (1704), Isaac Newton expounded on the relationship between amplitudes in the color spectrum and notes within a scale, thus presenting the first physical demonstration of a color-tone analogy. The logical implementation of that theory into practice was a device capable of the musical visualizations of colors and/or tones. The first one to follow this idea was the French mathematician Louis-Bertrand Castel (1688–1757), who developed a color organ he called Clavecin oculaire, according to him inspired by the composer Jean-Philippe Rameau.^[1] All further color organs in the 18th century resulted out of the reception of Castel’s ideas in France, Germany, and England.

In 1739, Castel’s Clavecin became known in Germany through a brochure issued by the composer Georg Philipp Telemann, who had visited Castel in Paris and viewed a preliminary version of his instrument.^[2] The naturalist Johann Gottlob Krüger thereupon occupied himself with his own Farbenclavecymbel, and in 1743 published the first ever sketch of a color organ.

An anonymous (Ocular Harpsichord), Edme-Gilles Guyot (Musique oculaire), Johann Samuel Halle (Farbenleyer), as well as Karl von Eckartshausen also designed similar devices modeled on Castel’s Clavecin. By the late eighteenth century, the notion of an emotional impact of the colors had become increasingly important.

Halle’s thoughts in the descriptions of his instrument seem to echo Moses Mendelssohn’s Über die Empfindungen (1755), while the mystic Eckartshausen discussed the color organ in a music-therapeutic context.