This study investigates how interdisciplinary pedagogy can employ songwriting as a medium for students to articulate their observations and emotions, thereby addressing contemporary educational imperatives of aesthetic cultivation and social-emotional learning (SEL). Situated within the broader context of competency-based and holistic education, the research positions art education not only as an enrichment activity but as a critical avenue for fostering cognitive growth, emotional expression, and the development of students’ aesthetic sensibilities.Through the course design of “Singing What I See”, this study reorients conventional teacher-centered instruction toward a student-centered paradigm, empowering learners to transform their personal observations and emotions into original songs. By transcending the limitations of traditional one-way knowledge transmission, the course cultivate a learning environment that privileges student agency, nurtures critical reflection, and fosters collaborative engagement.The study adopted action research and classroom observation as its methods. Sixth-grade students, approximately one hundred in total, were grouped according to their musical and linguistic abilities and engaged in lyric-writing and songwriting activities. The instructional design integrated twelve art lessons and three language lessons, during which students collaboratively composed and performed their original songs in groups. Throughout the process, the research documented not only students’ learning progress and final products but also the transformations observed in their interactions and emotional exchanges.The findings indicate that the interdisciplinary curriculum substantially enhanced students’ engagement and creativity. Beyond facilitating cross-disciplinary learning in language and music, the process also fostered stronger collaborative relationships among students. Most notably, students demonstrated growth in self-awareness and social-emotional regulation, underscoring the distinctive value of art and music education in cultivating SEL competencies.In addition, this study highlights the potential of interdisciplinary arts and music education within competency-based curricula. On the one hand, it enriches the substance of music education; on the other, it advances language learning and emotional development, thereby embodying the principles of interdisciplinary and holistic learning. These findings also align with the global emphasis on interdisciplinary learning and SEL, offering a valuable model and inspiration for integrating the arts and music with other subject areas across diverse educational contexts.