THE NATURE AND DEVELOPMENT OF CERTAIN FUNDAMENTAL MUSICAL SKILLS WERE STUDIED. THIS STUDY FOCUSED ON AURAL PERCEPTION AS AN INTEGRAL FACTOR IN THE CHILD'S MUSICAL DEVELOPMENT. TWO MAJOR ASPECTS OF THIS 5-YEAR STUDY INCLUDED (1) LONGITUDINAL STUDY OF THREE GROUPS OF CHILDREN AND (2) A SERIES OF 1-YEAR PILOT STUDIES DEALING WITH RHYTHM, TIMBRE, AND HARMONY. INDIVIDUAL TESTS WERE ADMINISTERED TO THE SUBJECTS REQUIRING AN OVERT MUSICAL RESPONSE TO AN AURAL PRESENTATION OF THE TEST ITEM. THE TESTS, AND RESPONSES WERE TAPE RECORDED TO INSURE MAXIMUM UNIFORMITY OF TESTING PROCEDURES AND SUBSEQUENT PROCESSING. COMPLEX MELODIC, RHYTHMIC, AND HARMONIC ITEMS WERE FOUND TO BE DIFFICULT FOR YOUNG CHILDREN AND TO SOME DEGREE FOR OLDER CHILDREN. RESULTS OF THE STUDY INDICATED THAT THE ABILITY TO IMITATE THE PRESENTATION OF CERTAIN MUSICAL IDEAS WAS NOT A MEASURE OF THE UNDERSTANDING OF SUCH IDEAS. (RS)