This study examines the impact of instrumental music study and group chess lessons on the standardized test scores of suburban elementary public school students (grades three through five) in Levittown, New York. The study divides the students into the following groups and compares the standardized test scores of each: a) instrumental music students b) scholastic chess players c) students who participate in both chess and music and d) students who take part in neither scholastic chess nor school music lessons. The standardized tests used are the New York State Mathematics (grades three, four, and five), English Language Arts (grades three, four, and five), Science (grade four), and Social Studies (grade five) assessments. The variables of music and chess participation are examined in the normative data of each group, along with gender and weekly instrumental music/chess practice time. Data gathering consists of surveys, teacher records, and official school reports. The primary hypothesis postulates that students who participate in weekly chess lessons and/or weekly instrumental music lessons score significantly higher on standardized tests (p < 0.05) in all assessments in all grades, with students who participate in both activities scoring the highest in all groups. The secondary hypothesis postulates that students with the most weekly practice time in chess or music have the highest New York State English Language Arts and Mathematics test scores among chess players and musicians. The results indicate that there is a small statistically significant difference (p = 0.033) in favor of students who participate in chess and/or music at the fourth grade level versus those who do not. Also, students with the highest weekly practice times and practice frequencies in music earn significantly higher test scores on the mathematics assessment (p = 0.001 and p = 0.02 respectively). There is a significant difference in gender among non-chess players/non-musicians, where girls outperform boys on the English Language Arts (p = 0.022) and boys outperform girls in mathematics (p = 0.025). However, these gender differences are not discernible in the test scores of musicians or chess players. Further research is suggested to explore the implications of these findings. [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.]