Intended as a memorial to Robert G. Sidnell, this special issue contains articles about areas of music education which he promoted. In "The Dimensions of Research in Music Education," Sidnell concluded that music education research encompasses all humanistic disciplines as well as the behavioral and social sciences. James Carlsen, in "Framework for Research: An International Perspective," presents a taxonomy of instructional systems and research studies that examine theories under one or more components of each system. "Recent Research Pertaining to Psychomotor Skills in Music," by Steven Hedden, examines research published since 1978 concerning the relationship of motor skills to music education. Henry Cady analyzes how the meaning of a work of art develops in "The Problem of the Rational in Music," and Richard Colwell suggests that a person's educational philosophy is the most important dimension of teacher education in "Music Education and Philosophy." Assessing music education is examined by Thomas Tunks in "Evaluation in Music Education: The Value of Measurement/The Measurement of Value." The need for the expansion of music education research is considered by George Duerksen in "Research and Music Education: Needs for the Next Decade," while David Williams describes music expression as a social behavior in "Do Our Models for Music Research and Teaching Reflect Our Human Social Nature?" Kate Grieshaber considers the fundamental nature of rhythmic abilities in "Children's Rhythmic Tapping: A Critical Review of Research." (JHP)