There are no figures available, but if a survey were made, possibly more people would be found engaged in the study and teaching of piano than any other musical instrument. It is much to be desired for both teachers and students to have an intimate acquaintance with the principles underlying the structure of modern piano technique. The situation as it generally exists contrasts sharply with the ideal situation. The ignorance of this important phase of piano study causes an enormous annual waste of time and money on the part of students. With an adequate technical knowledge, teachers, instead of allowing their pupils to practice blindly and mechanically, would be able to explain the reason for each movement they ask them to perform. Many failures in both classes occur because of the lack of understanding of what piano playing requires.