Alfred Day M.D. (1810 – 1849) was a British homeopathic physician and noted musical theorist.

Day was one of the signatories to a letter sent to the London Morning Post newspaper in March, 1845 that sought to distance British homeopathy from the dietetic treatment used by Dr. Paul Francois Curie in a case that had resulted in the death of the patient. The other homeopaths who signed the letter repudiating Curie’s methods were: Frederick Hervey Foster Quin, Hugh Cameron, John Darby Charles, J. Chapman, John James Drysdale, Harris Dunsford, Thomas Engall, Joseph Gilioli, James Walter Goodshaw, William Hering, Claudius B. Ker, Charles Joseph Berry King, William Hamilton Kittoe, Henry Rider Madden, Victor Massol, William H. Mayne, George Newman, John Norton, Samuel Thomas Partridge, Edward Phillips, Robert Walker, and William Wardroper.

Alfred Day:

musical theorist, was born in London in January 1810. Though showing very strong musical tastes, in accordance with his father’s wishes he studied medicine at London and Paris, and, after taking a medical degree at Heidelberg, settled in London in practice as a homoeopathist. For several years he devoted himself during his leisure hours to maturing a plan which he had conceived for forming a complete and logical theory of harmony out of the existing mass of isolated and often inconsistent rules. The results of his study were given to the world in ‘ A Treatise on Harmony,’ published in 1845. The work was unfavourably received, though its originality attracted even then the attention of a few scientific musicians. One of these, Sir George Macfarren [q. v.], subsequently adopted much of Day’s theory, and mainly by his advocacy the work has become a recognised authority on many of the subjects of which it treats. ‘The speciality of the treatise is twofold: firstly, the standard laws of the ancient, strict, diatonic, artificial, or contrapuntal style are collected and systematically codified . . . and they are distinguished entirely from those of the modern, free, chromatic, natural, or harmonic style; secondly, though the natural chord of the dominant seventh had been more or less freely used for . . . three and a half centuries prior to the appearance of this book . . . no systematic principles of fundamental harmony had ever been deduced from the phenomena that bring that remarkable chord within the resources of the musician. . . .Day perceived that the acoustical laws of harmonic evolution were the genesis of all music; that the natural chords springing from the dominant were imitable by the appropriation of the chromatic element upon other notes in the key; and that these chromatic imitations of the dominant were identified with the key by their resolution upon, or progression into, other chords common to the same tonality’ (Macfarren, Preface to Day’s Treatise, 2nd edit). In almost every branch of the scientific basis of music Day proposed some reform, and though many of his theories are open to attack, yet on the whole the work is one which no musician can neglect to study. Day died of heart disease, after a long illness, on 11 Feb, 1849.
[Day’s theories are ably discussed by Mr. C.H.H. Parry in an article in Grove’s Dictionary of Music, i. 436; Musical World, 17 Feb. 1849] W.B.S. [William Barclay Squire]