the electronic organ developed throughout the 20th century. some pipe organs were replaced by digital organs because of their lower purchase price, smaller physical size, and minimal maintenance requirements. in the early 1970s, rodgers instruments pioneered the "hybrid" organ, an electronic instrument that incorporates real pipes; other builders such as allen organs and johannus orgelbouw have since built hybrid organs. allen organs first introduced the electronic organ in 1937 and in 1971 created the first digital organ using cmos technology borrowed from nasa which created the digital pipe organ using sound recorded from actual speaking pipes and incorporating the sounds electronically within the memory of the digital organ thus having real pipe organ sound without the actual organ pipes.