In proposing this conservative approach through psychophysical measurements, I do not wish to belittle the insight, common knowledge and theories of inheritance which have been obtained by observation and statistics in terms of musicality as a whole--as in biography, autobiography and letters of great musicians or in the study of musical families. But we are confronted with the fact that these deal largely with unanalyzed situations so completely covered by factors of environment and training as to make them useless for strictly scientific purposes. Nor would I belittle the significance of general traits, such as musical intelligence, creative imagination and the artistic temperament, or facilities for specific skills, such as sight reading, and the memorizing of repertoires. We know a great deal about these and unquestionably have the right to assume that they have an hereditary basis. But scientific studies in heredity may be more properly approached through the simpler and more elementary capacities. For scientific purposes, we cannot, of course, mix basic measurements and current ratings of musical achievement. There have been numerous approaches to this subject from the musical-achievement point of view, and these have furnished many suggestive leads and probably point to unquestioned facts about the inheritance of musical talent. But the science of genetics rightly rests upon and demands the isolation of specific factors which can be measured; and for that purpose the musical geneticist must, for the present, sacrifice many otherwise interesting approaches from the point of view of rated achievement and be willing to await the laying of foundations of rigidly conducted measurements which can be described, interpreted, and verified. THOUGHT REVIEW General Principles (1) The question is not whether or not musical ability _is_ inherited, but _how_ it is inherited. (2) The musical heritage through each parent is transmitted through a single germ cell. (3) The mechanism of musical heredity lies in the organization of the genes in the twenty-four pairs of chromosomes found in this fertilized germ cell. (4) Scientific principles of musical inheritance can be established only through experiment and measurement of specific capacities; they cannot be derived from studies of musical achievement alone. (5) We come into the world a fully-equipped organism which is evolved from the germ cell before birth. (6) This hereditary equipment is prolific in possibilities; at best, the musical life can develop only through a small part of these inherited resources. (7) Defects in the inherited equipment set corresponding limits to musical achievement.