Experimental musical instrument including intonarumori ("intoners" or "noise machines"), to create "noises" for performance. Unfortunately, none of his original intonarumori survived World War II. Replicas are being made though. Léon Theremin was a Russian inventor, most famous for his invention of the theremin around 1919–1920, one of the first electronic musical instruments. The Ondes Martenot is another early example of an electronic musical instrument. The luthéal is a type of prepared piano created by George Cloetens in the late 1890s and used by Maurice Ravel in his "Tzigane" for luthéal and violin. The instrument can produce sounds like a guitar or a harmonica,
Musical instrument popular music, and the instrument makers responded accordingly. Beginning in about 1400, the rate of development of musical instruments increased in earnest as compositions demanded more dynamic sounds. People also began writing books about creating, playing, and cataloging musical instruments; the first such book was Sebastian Virdung's 1511 treatise "Musica getuscht und ausgezogen" ('Music Germanized and Abstracted'). Virdung's work is noted as being particularly thorough for including descriptions of "irregular" instruments such as hunters' horns and cow bells, though Virdung is critical of the same. Other books followed, including Arnolt Schlick's "Spiegel der Orgelmacher und Organisten" ('Mirror of Organ Makers