Lots of "sub" sounds in the country, as well as the city, air movement for one: different sounds wind makes rushing thru different trees, bamboo, ripe barley field, ripe corn; ryhthmic sounds, like waves, insects and woodpeckers; melodic sounds of birds, moving water; even the distant sound of people when there aren't any, often heard over rushing water. Country songs reflect these organic sounds...even fast numbers are often basically the same kinds of sounds, only speeded up.

Urban sounds are often manmade--more staccato, more frenetic, more percussive which tends to create more aggressive music.

Both vast oversimplification, of course, but I do think background ambiance has a lot to do with both the music we write and the music we sing/play.