As the digital transformation of education deepens globally, integrating emerging technologies into basic education has become a critical pathway for curriculum innovation. This study aims to empirically evaluate the effectiveness of digital tools in empowering primary school music education, specifically focusing on improving students' musical academic performance and classroom engagement. Adopting a rigorous quasi-experimental design within a mixed-methods framework, this study selected 389 elementary students from Grades 1 to 6 in a primary school in Western China. Participants were assigned to either an experimental group or a control group. To address internal validity concerns, extraneous variables—including instructors, teaching syllabi, and class activity duration—were strictly controlled and kept consistent across both groups to ensure that observed effects were attributable to the intervention. The experimental group underwent a 16-week intervention utilizing the "Mohuan AI" music education platform, which features gamified rhythm exercises, intelligent sight-singing evaluation, and real-time visual feedback, while the control group adhered to the traditional teaching mode. Data collection integrated quantitative pre- and post-tests assessing musical academic performance (encompassing music theory knowledge and sight-singing skills) with qualitative data derived from classroom observations and semi-structured interviews to triangulate findings. Statistical analyses, employing independent and paired sample t-tests, indicate that: (1) The experimental group achieved significantly higher post-test scores than the control group, confirming the efficacy of digital tools in enhancing both theoretical understanding and practical sight-singing abilities; (2) Grade-level disparities were observed, with Grade 6 demonstrating the most substantial improvement in overall performance, while Grade 5 showed less significant gains in written theory, suggesting that students' cognitive development stages influence the reception of digital interventions; (3) Qualitative analysis revealed that digital tools significantly reduced cognitive load through multi-sensory interaction, thereby boosting students' intrinsic motivation and classroom participation. Furthermore, the intervention facilitated a pedagogical shift, enabling teachers to transition from knowledge transmitters to learning facilitators. The study concludes that digital tools effectively empower primary music education by not only improving academic achievement but also promoting educational equity and core literacy, though pedagogical strategies must be adaptively tailored to the specific cognitive needs of students across different age groups.