_New substitutes for existing instruments._ Substitutes for all instruments now extant may be expected to come mainly through the development of electrical construction, although many forms of mechanical devices may be used independently or with the electrical. There is no question at all but that with such resources, substitutes for a stringed instrument, a wood wind, a horn, and many varieties of traps and accessories can be built so as to embody increased musical resources. The principles for the construction of such a violin, flute, trumpet, or any other single instrument are already in hand. The construction may embody such mechanical devices as strings, membranes, and pipes; but if so, these will be electrically energized. We may predict that substitutes for single instruments will increase in great variety and that very simple forms adapted to age and advancement in the playing of specific instruments can be supplied. The variety of means for stunt performances may be increased to an alarming degree. _New ensembles._ Another significant line of development will undoubtedly appear in the matter of ensembles. By the utilization of electrical construction, a single series of generators may supply the harmonic structure of a tone from each and every instrument now in use. Thus, a bank of sixteen violins may be supplied from this single source and sixteen individual violin tones may be played in identical pitch, even dynamics, equal temporal movements, and uniform tone quality. Such uniformity would however be of limited musical significance. The important thing musically is the fact that in such a bank any desired form of artistic deviation or differential enrichment may be provided for. The same would apply to wood winds, horns, bells, drums and other percussion instruments in large part. Where further representation of mixed tone, inharmonics, or noises are demanded, they may be added. The substitute for a drum can increase the precision and range of the drum sound without the use of the drum, as, for example, in the present "Novachord". Thus, it is conceivable that with the exception of certain unforeseen limitations, the instrumentation of an entire orchestra or band can be built into a single unit operated from a single console. From what we have seen in the way of marvelous demonstrations in recent years it is reasonable to suppose that entirely new types of complex instruments will be invented, bringing to music hitherto unknown resources. Furthermore, with the instrumental music as such, provision may be made in the instruments for words in speech and song, and the visual presentation of dramatic action in color, relief, and movement which may be controlled from the console. The goal of embodying in a single instrument or coupling units of instruments the means of performing chamber music, orchestra, band, and the grand opera, is without doubt no wilder prediction than was the prediction of radio or airplane a few years ago.