An experimental musical instrument is a musical instrument that modifies or extends an existing instrument or class of instruments, or defines or creates a new class of instrument. Some are created through simple modifications, such as cracked cymbals or metal objects inserted between piano strings in a prepared piano. Some experimental instruments are created from household items like a homemade mute for brass instruments such as bathtub plugs. Other experimental instruments are created from electronic spare parts, or by mixing acoustic instruments with electric components.

Luigi Carlo Filippo Russolo was an Italian Futurist painter, composer, builder of experimental musical instruments, and the author of the manifesto The Art of Noises (1913). Russolo completed his secondary education at Seminary of Portograuro in 1901, after which he moved to Milan and began gaining interest in the arts. He is often regarded as one of the first noise music experimental composers with his performances of noise music concerts in 1913–14 and then again after World War I, notably in Paris in 1921. He designed and constructed a number of noise-generating devices called Intonarumori.