In the present state of scientific knowledge in general, it may appear incomprehensible, to those who hare not pursued it in the direction of music, that we should have arrived beyond the middle of the nineteenth century of the Christian era without any work having yet appeared which has set forth even the elements of that science in a light which has carried conviction and met with general acceptance. I am not speaking here of the excellent treatises of Sir John Goss, John Hullah, Henry Lunn, Henry Banister, Alexander Hamilton, &c. These, and numerous others, do not profess to treat of the recondite view of the subject, but solely to supply the young student with practical applications of accepted facts. What is still wanting, despite numerous endeavours, is a work which shall convincingly trace the materials and combinations of the Harmonist to their true source, and show him (as I believe to be the case) that those materials and combinations are not arbitrary and conventional, but are supplied by Nature herself—thus enlarging his views, and, in fact, laying before him all of which, as a Harmonist, he can avail himself.