In traditional music lessons, students are often only allowed to play the melody on the recorder while the teacher plays the piano or provides accompaniment via an e-book. Students are always the main focus, but they don't understand the importance of accompaniment in enriching the music. This lesson, through chord progressions, allows students to experience how adding accompaniment enriches music. Using the organ in the "Playful Sound" app, students can increase the thickness of the sound and overcome spatial and instrumental limitations. This allows them to appreciate the richness of sound and the importance of accompaniment, gaining a deeper understanding and experience of the charm of the king of instruments, the pipe organ.