In the United States, due to the maturation of the musical culture at the turn of the century, many departments of singing transitioned into more comprehensive music departments. Many studies of music education were carried out during the transition period from singing departments to music departments, and various claims were made in music educational journals. Thus, it could be valuable to analyze music education journals published during this transition period to clarify the philosophy underlying the establishment of music departments. The current study focused on the Music Supervisors’ Journal, which was a music education journal published before the formation of music departments. The content of the journal was categorized into three categories: (1) reporting on the content of the meeting of Music Supervisors’ National Conference; (2) posted advertisements; and (3) articles by people involved in music education. In this research, I examined the titles of articles by people involved in music education and the types of articles that tended to be published in the journals at the time. This analysis was used to examine trends in music education in the United States at the time. The results revealed that, from 1921 to 1929, there was a tendency to publish many articles, tests, and measurements in music education. In addition, there was a department for each field, including singing, instrumental music and music appreciation, and related articles were published on a continuous basis.