The purpose of this quantitative, causal-comparative study was to compare the effect elementary music and visual arts lessons had on third through sixth grade standardized mathematics test scores. Inferential statistics were used to compare the differences between test scores of students who took in-school, elementary, music instruction during the same semester state standardized mathematics tests were administered and those who took in-school, elementary visual arts instruction during the same semester standardized mathematics tests were administered. The students attended seven elementary schools in the same North Alabama school district. The research questions were: (a) Does participation in elementary school music lessons have a greater positive effect on the proportion of third through sixth grade students who score Level III and Level IV on the ARMT mathematics test compared to third through sixth grade students participating in elementary school visual arts lessons? and (b) Does participation in elementary school music lessons have a greater positive effect on the mean SAT-10 mathematics test scores of third through sixth grade students compared to third through sixth grade students participating in elementary school visual arts lessons? There results indicated there was not a statistically significant difference in the analysis of the ARMT scores; however, the analysis did reveal that on average a greater proportion of students scored higher on the mathematics section of the ARMT when taking school music lessons compared to visual arts lessons. The analysis results of the SAT-10 scores did yield a statistically significant difference. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]