The relativity of all these key-colour associations was illustrated during a debate on the whole subject organised in London in 1886 by the Journal “Musical Opinion”. That section of the audience that maintained the definite existence of “key colour” by which it could aurally identify a key was submitted to a test, a well known piece being played in both G and Ab, to which they applied and defended their usual G and Ab associations, maintaining that the transposition had totally changed the key colour. The meeting broke up in recrimination and disorder on its being revealed that the piano possessed a mechanical transposing device, so that whilst those present had seen the performer playing in Ab they had heard her playing in G major as before.

P. A. Scholes, The Oxford Companion to Music, Oxford, Oxford University Press, 1939, pp. 183-184, cited in J Powell & N Dibben, “Key-Mood Association: A Self Perpetuating Myth”, Musicae Scientiae, vol. 9., 2005, pp. 289-311., 10.1177/102986490500900208, https://www.researchgate.net/publication/258173253_Key-Mood_Association_A_Self_Perpetuating_Myth (accessed 25 April 2023).