This action research aimed to explore ways to empower Korean preservice music teachers’ competency of Technological, Pedagogical and Content Knowledge (TPACK). To fulfill this aim, the 15-week TPACK-framework-based music education course was developed and executed with four preservice music teachers at a graduate school of education in Seoul, Korea. The study results are as follows: First, the opportunity for self-reflective activities with drawing and writing practices, guided by the TPACK framework, fostered the participants’ self-cultivation as a competent teacher of TPACK. Second, the participants’ flipped-learning teaching demonstration practices in various music educational settings, such as performance, appreciation, and composition, empowered their practical TPACK competency. Finally, the opportunity to explore and apply technology in music teaching and learning contexts empowered the participants’ sense of TPACK competency and efficacy. Especially, the exploration of new teaching tools is particularly valuable at a time when new technological breakthroughs are transforming classrooms across the board.This study contributes to bridging the TPACK theory to music teacher education practice. It also contributes to the underrepresented TPACK-related research in Korean preservice music teacher education and qualitative theory and practice.