As structuralism gave way to Gestalt psychology and behaviorism at the turn of the century, music psychology moved beyond the study of isolated tones and elements to the perception of their inter-relationships and human reactions to them, though work languished behind that of visual perception.[1] In Europe Géza Révész and Albert Wellek developed a more complex understanding of musical pitch, and in the US the focus shifted to that of music education and the training and development of musical skill. Carl Seashore led this work, producing his The Measurement of Musical Talents and The Psychology of Musical Talent. Seashore used bespoke equipment and standardized tests to measure how performance deviated from indicated markings and how musical aptitude differed between students.