The effect of a structured program of musical training on the musical abilities of preschool children from disadvantaged environments was investigated. It was hypothesized that, if the musical abilities of such children could be improved sufficiently, they might then be able to enter elementary school on a level commensurate with that of their more fortunate peers. The project was conducted in three phases: pretest, instruction, and posttest. During the pretest phase, each child was given an individual musical concept performance test to determine his initial level of musical ability. The disadvantaged children were also given an individual Stanford-Binet Intelligence Test. Four groups of children were employed: two advantaged and two disadvantaged. One of the advantaged and one of the disadvantaged groups served as control groups, and the other two were exposed to a 20-lesson series of musical concept instruction. After the training phase, the same test as used in the pretesting phase was employed for posttesting. A two factor A x B design was employed for the analysis of the simple, main, and interaction effects. Marching, clapping, and rhythm echo games were effective techniques for teaching rhythm concepts. The results suggest that such a structured program effectively raises the level of musical ability of both disadvantaged and advantaged children. (Author/CK)