Russolo's The Art of Noises guides modern composers toward a new aesthetic regarding the incorporation of existing sound and "sound objects" into musical compositions. regarding a letter from a friend in the trenches of WWI, Russolo shows us how even the sounds and sights and smells of war can be looked at as a bizarre performance orchestrated by horses, machine guns, signal lights, and cannons.
It seems as though Russolo's desire to seek new media for composition stems from a feeling that existing instruments and standards of instrumentation are inadequate for expressing emotions of a world in an age of machines and mechanical rhythms.
It is interesting to note that Igor Stravinsky, who was composing around the same time, said that he felt that the twelve notes in the standard equal temperament scale and the standard system or rhythmic notation could allow him infinite possibilities for composing music. Stravinsky's music was considered to be revolutionary in his own time and even today a lot of people think that it's pretty far out. right on.
people have been incorpoerating natural sounds into music for centuries. the sounds of birds, streams, wind, cannons and other janx have been written into music by haydn, handel, mozart, bach and others.