This study is a comparison of the Ohio Proficiency Test (OPT) results of instrumental music students and their noninstrumental classmates according to socioeconomic status (SES) over time. Subjects ( N= 15,431) were students in the Columbus Public Schools in Ohio, whose fourth-, sixth-, and ninth-grade OPT results were compared with others of like SES on the subjects of citizenship, math, science, and reading. Results show that instrumental students outperformed noninstrumental students in every subject and at every grade level. Instrumental students at both levels of SES held higher scores than their noninstrumental classmates from the fourth grade, suggesting that instrumental music programs attract higher scorers from the outset of instruction. Results also show a pattern of increased achievement by lower SES instrumental students, who surpassed their higher SES noninstrumental classmates by the ninth grade in all subjects. September 15, 2005 March 20, 2006