This study was conducted in order to verify differences of the impact between child- initiated singing activities and teacher-initiated singing activities on building children’s musical concepts. During the child-initiated singing activities, children actively created songs, added various rhythms and melodies to their songs, and participated in singing activities with a positive attitude through cooperative inter- actions with teachers. Participants were 60 children, all five years old, attending a kindergarten in a middle-class residential area in Seoul, Korea. Child-initiated singing activities were utilized for the experimental group, and teacher-initiated singing acti- vities for the comparison group. Children were given pre- and post-tests to measure their ability to understand musical concepts with the Project Spectrum Assessment of Music Domain (Krechevsky, 1998). The collected data was coded for the SPSS software (SPSS Inc., Chicago, IL) and analyzed by an analysis of covariance (ANCOVA). The data analysis showed a signi- ficant difference between the experimental group and comparison group. The experi- mental group, which experienced child-initiated singing activities, displayed greater improvement in their understanding of musical concepts. According to our findings, child-initiated singing activities have a positive impact on building children’s musical concepts.