This pilot project proposed to construct a test or battery of tests to measure (1) the music discrimination abilities of school children aged 12 and under; (2) children's understanding of such basic concepts as rhythm, melody, and harmony; and (3) the ability of children to apply these concepts in music listening. Musical excerpts representing a balance among Baroque, Classical, Romantic, and Modern-Contemporary stylistic periods, which ranged in length from 6 to 30 seconds, were copied and "mutilated" to produce a pool of 243 possible test items. To compose mutilated versions, only one of the elements--rhythm, melody, or harmony--was changed, while a distortion was devised that was inherently weak by being erratic, inconsistent, illogical or mixed up. Items were recorded and evaluated on a five-point scale of difficulty for elementary pupils. Based on three out of four earlier experimental tests, two forms of the fifth test--composed of two parts--were administered (1 week apart) to the same 448 elementary school children. Evaluation of the test and recommendations for improving it were then made. [Data on this test, conclusions, a bibliography, sample answer forms, lists of participating schools and personnel, tables of results, and figures containing mutilations are provided. Not available in hard copy due to marginal legibility of original document. (JMC)]