Final answer:
Willem van de Wall was instrumental in the early development of music therapy, establishing the National Foundation of Music Therapy in 1941, authoring influential texts, and expanding the use of music in rehabilitation during the mid-20th century.
Step-by-step explanation:
Willem van de Wall was active primarily in the early to mid-20th century. He is known for creating the National Foundation of Music Therapy in 1941. This foundation was established to support the development and practice of music therapy, an area where van de Wall was a pioneering figure. During the period from 1925-1932, van de Wall initiated the use of music therapy in institutional settings, beginning with his work in various state institutions in Ohio. In 1936, van de Wall published his influential book, 'Music in Institutions'. By 1938, his work had gained significant recognition, leading to the expansion of music therapy practices. In 1944, he worked as a consultant to the Army Air Force Convalescent Training Program, which helped solidify music therapy's role in rehabilitation. The following year, in 1945, he played a crucial role in organizing the first recorded music therapy seminar at Michigan State University. Finally, in 1953, Willem van de Wall passed away, but his legacy continued through the foundation and the field of music therapy he helped establish.