The first third of the 20th century is a significant period in the history of piano pedagogy, bringing many innovations and transformations. The reform approaches to piano teaching are extremely modern and continue to have an impact today. The extensive source material, which has appeared in book form and in a large number of articles in professional journals as instructions for piano teachers, is being compiled and systematically evaluated for the first time in a comprehensive manner. The discussions focus on the question of how piano instruction is theoretically planned and thus musically didactically oriented. The key developmental trends in piano pedagogy are presented against the backdrop of the intellectual historical context.