This book explores the transformative impact of sound technology in the early twentieth century, focusing on its role in the production and transmission of music. It examines how music has been used for information, relaxation, and creating ambiance, as well as the formats through which sound technology has been consumed and produced. The book also highlights the use of various formats tailored for individual, small group, large group, national, and international audiences, addressing both formal and informal applications for enjoyment and information.