The term “Musical Exposition” may be taken to include all the various means adopted for representing to others the work of the musical brain, such as (1) The notation employed for representing it to the eye, and thus stereotyping it for common use; (2) The vocal or instrumental processes by which it is reproduced to the public ear, and eventually made to assume in the brain of the listener the shape in which it originally presented itself to the internal ear or musical imagination of the composer; and (3) The methods by which the arrangement and assortment of sounds which we call music—that manipulation, so to speak, of the elementary material at command which constitutes composition—is explained, justified, and taught to those who wish to learn it.