_Timbre._ The most significant new feature is, of course, the extension and control of richness in timbre and sonance, which constitute tone quality. The range of timbre changes may extend from a pure tone to the inclusion of even more partials than the ear can hear, possibly thirty or forty, with an infinite variety of harmonic forms of distribution between these extremes. Great innovations through inharmonic and aperiodic sounds are coming. It is now possible to maintain a uniform timbre which gives an element of dignity and stability to the tone in a sustained note. But since deviation from the regular is of far greater importance, flexibility of tone quality is even more desirable. This flexibility in timbre for the duration of the tone which determines tone quality, technically called sonance, may be provided for by various devices. For example, in the present "Novachord", the various forms and degrees of vibrato are at the command of the player and are based on scientific investigation leading to specification for this musical ornament. Given the mechanisms for harmonic structures and inharmonics, we need only the addition of rough noise of various kinds to make the tone realistic. The timbre available in the musical instrument will therefore run from the pure tone to the roughest noise. In the above I have attempted to present a picture in rough outline indicating present trends and predictable futures for music through the improvement of musical instruments. The instrumentalist can point out many features not here mentioned. The musician may yearn for new resources in his musical medium for which he can now lay down specifications. The listeners must be prepared for startling innovations and thrilling new sources of pleasure in music. It will take generations to finish the theoretical picture I have here sketched in bold outline--but let us look forward to a progressive unveiling and revelation of possibilities. But take no alarm--the horse, if not the buggy, will survive. THOUGHT REVIEW General Principles (1) We are entering upon a new era for musical instruments. (2) Present instruments will be improved, new instruments will be innovated, new ensembles will be achieved. (3) Conforming to this progress, present music will be adapted and new types of composition will appear. (4) In this changing order musical tastes will undergo significant changes. (5) The composer may now specify new conceptions of desired features, and the technicians will provide them. (6) Instrument makers will be able to produce or reproduce any musical sound in nature or art. Consider These Questions (1) If the violin strings are mounted on a perfect resonator with different shape from the present violin, will that be a violin?