The objective of the study is to investigate various factors affecting the effectiveness of a music program at secondary school in Hong Kong. Two secondary schools are involved in the investigation. The principals, the music teachers, and the students are being interviewed separately with different sets of questions. In-depth questions concerning the rationale are being considered. The data collected are analyzed and findings of the key factors affecting the effectiveness of a music program include the leadership of the principal, the vision and involvement of the music teacher, as well as the management skill of both the principal and music teacher involved in complicated situations. It is, therefore, concluded that education of the principal and music teacher, which forms the two key factors effecting the effectiveness of a music program, should include also studies in management and leadership courses in addition to their own professional training. Furthermore, team work, availability of extra facilities, collaboration among colleagues of different subject areas, and many other interrelated elements are also essential factors for a successful music program.