The range of possibilities may be illustrated in the case of a generator for a single tone. A few years ago a graduate student came to me and said that he wanted to take as the subject for his doctoral dissertation the building of an electrical organ. I told him that if he would build a generator for a single key I would assure him a stipend for three years and all the needed facilities of the Iowa acoustical laboratories. He accepted and made good to an extraordinary degree. The tone generator he built is composed of the first sixteen partials, _i. e._, a fundamental and fifteen overtones in harmonic series, each virtually a single pure tone. The number of partials, the form of distribution of partials, the amount of energy contributed by each partial, the phase relationships of the partials, and the fundamental pitch are under control and may be set up in any combination. With this number of variables, mathematicians will say that any desired tone quality of harmonic structure up to more than a million kinds of tone can be produced. The ear cannot hear all these differences, but the instrument provides keys for as many steps in the entire series as may be musically significant, and the tone at each of these steps can be specified for production, described, and repeated indefinitely. Thus, it is possible to make the instrument speak any vowel in so far as it involves harmonic structure, and the harmonic composition of any musical instrument may be imitated. Provision for inharmonic elements and noise accessories which are necessary both for vowels and instruments can, of course, be installed with this generator. Given one tone with such a range of possibilities, it is but a series of logical and fairly simple steps to provide a complete musical instrument by simply multiplying notes of this kind. This is the type of development we see now in a variety of electronic instruments. _The improvement of existing instruments._ Musical instruments now in use can be improved. We now have the means for the technical analysis of the character of the tone produced by any instrument as a whole or by any particular feature in its construction, so that faults and limitations can be definitely allocated. Recent investigations have revealed faults in the best of violins. Some of these faults or limitations may be corrected by change in construction. For practical purposes, a 1939 violin of American make may approximate the good qualities of the Stradivarius, and there is no doubt that improvements could be made upon the famous old instrument. The same is true in principle of all individual musical instruments now in use. One of the obstacles, however, will be the unwillingness of many musicians to face the innovation of change in the looks of their beautiful instruments so tenderly loved and guarded.