Stocking the open classroom with learning materials is more than a matter of choosing and buying; it often means scrounging for, stumbling on, and inventing. And it also involves careful analysis, evaluation, and planning to make sure that the materials are appropriate and stimulating for a particular group of students at a given time, accommodating a wide range of activities, interests, and ability levels. It must be remembered, though, as the Education Development Center has pointed out in Instructional Aids, Materials, and Supplies, that “instructional aids and materials have no inherent power. A classroom can offer a rich material environment yet be sterile and lifeless. Materials … acquire value only as they are acted upon by children's and teachers' minds.” In the following article, Helen Loftin Cornell, elementary music teacher with the Metropolitan Nashville Public Schools, offers suggestions for developing music materials for the open classroom.—Ed.