IN 1930 THE COLLEGE of Music of Cincinnati embarked upon a program of testing, largely for purposes of prognosis. In supplement to an intelligence test, tests of personality traits, and standardized batteries of music talent tests, it was felt desirable to devise an experimental battery covering certain phases of musical ability not measured by the standardized tests, and involving an approach differing from the conventional one. This battery the writer was asked to construct, and the present report is an account of its evolution. The series embraced three divisions which were intended to tap tonal, rhythmic, and emotional functions respectively, plus a fourth purporting to measure acquaintance with musical literature. In the first division the testee was required to identify the mode (major or minor) of melodies, both accompanied and unaccompanied, and of chords. In the second division he was asked to tell the number of beats in a measure in certain musical selections. In the third he was told to choose, from descriptions offered, the one best fitting the mood of certain selections. In the fourth he was required to identify, by title and composer, a variety of musical selections. This first version of the test was played on the piano. Subsequently (1939), the battery was revised, enlarged, recorded, and standardized. Still later (1950) a short form was devised for use in teacher selection. Intended in its first form for college freshmen entering the music field, the 1939 revision was expanded into two forms, the first (Form A) for use in the tenth grade and above, the second (Form B) for use in the fourth through the ninth grades. In Form A there was added to the original test measuring rhythmic discrimination a second section in which the testee was asked to determine the presence or lack of constancy in the tempo of certain selections.