This study investigated factors associated with fourth graders' music knowledge assessed by the South Carolina Arts Assessment Program (SCAAP). Participants included 2,683 fourth-grade students nested within 35 elementary schools in South Carolina, United States. Hierarchical Linear Modeling (HLM) was used to examine both the student-level factors, including gender and ethnicity, and the school-level factors, including school ranking, poverty level, and participation in SCAAP. Results indicated that students' gender, ethnicity, school ranking, and school poverty were significantly associated with students' music scores. There was a statistically significant interactive effect of gender and school ranking and poverty on students' music scores. The findings could inform music teachers, school administrators, and educational policy makers to acknowledge these factors, adopt differentiated music instructional strategies, provide resources, and support students from diverse backgrounds in order to enhance students' learning outcomes in music education.