A pre-sound area consisting of experiments with cinematic technique and subject matter followed by golden age of popular film making that lapses into the state funded production of Socio political film

It is interweaving of the melodic lines with harmony

Artists usually use musical imagery to make their compositions more unique and alive. imagery in music used to "show" music. because of that listeners feel what happens. they see music like complete composition. they hear sounds, they feel movement, they see a picture. it makes music deep. that's why  musical imagery is very important and is used by artists so frequently.

The works of lewis hine and charles sheeler are examples of documentary photography or precisionism. they also depict american industrial sites and powerful machines.