DIY musical instrument building culture in Finland has its predecessors in folk culture, classical music, experimental music, underground culture, engineering, sculpture art, and workshop and leisure activities. In the past, people often built their own instruments if music instruments were not available for sale, if these were too expensive, or if they wanted to experiment and invent a new instrument. The chapter focuses on the early history of self-built electronic musical instruments and how DIY activity developed from the early years until the 1960s when radical change occurred in music, both technically and aesthetically.