It was in 1916, at a Summer School in Carbis Bay, Cornwall, that I first made the acquaintance of Kathleen Schlesinger – Fellow of the Institute of Archaeology in the University of Liverpool, and author of several important books, more than 125 articles on Musical Instruments in the Encyclopaedia Britannica – and of her latest and most important work, “The Greek Aulos,” published in 1939. Kathleen Schlesinger was due to give a series of lectures on the “Ancient Modes of Greece,” and I felt that here at last I might find an answer to what had been puzzling me for years. Now we all know that any musical sound gives forth a series of harmonics or overtones, which do not correspond with the tones of our modern keyboard. I used to listen in Paris to an aeroplane which flew over my studio about noon each day, and which produced the most beautiful harmonics from a deep fundamental tone of F. This is what is called the Harmonic Series, which we all learn about, but then put away in a pigeon hole in our brain, perhaps never to be called forth again, as we have no further use for it. Nevertheless, this Harmonic Series is the only musical law which is given us by Nature herself, and it rises first of all at the distance of an octave from the fundamental tone, then on to a perfect fifth, a fourth, a third etc., until we get such tiny intervals, called microtones, that the ear can no longer distinguish them. Now why do we not use some of these wonderful tones in musical composition? This was my query, for we know that when a trumpet or horn, for instance, is blown naturally, a part of this Harmonic Series is always to be heard. It was with delight, therefore, that I heard from Kathleen Schlesinger’s lectures that the Ancient Greeks did make use of these lovely tones, which she played to us on a Kithara, specially designed by her from a picture on a vase of this ancient Greek instrument.