One of the miracles about music is how a single sound from an instrument can evoke such powerful responses in us. For example, I happen to think the drum sound in Alanis Morrisette's "Head Over Heels" is perfect, a dry, flat "pow" that gets me right in the pit of my stomach. If I could make my heart beat with that sort of sound, I'd be a lot more sporty....
For evocative sounds though, I suspect there's nothing quite like a steel guitar, played with a slide by Mr Ryland Cooder. No matter how you slice it, slide guitar conveys America. A flat, tinny sound will speak of bleached wooden shacks in Mississippi, thick undergrowth and rusting cars by the side of the road.
But hit the "echo" button and all of a sudden the sound opens up, the vegetation vanishes and you're trying to thumb a lift on a single lane of blacktop somewhere in northern Texas. The blaring sky reaches down to slowly draw the strength out of you, a puff of wind bowls tumbleweed across the parched ground and you're not sure if that shimmering blob of darkness on the horizon is a car or a cow.
Ry Cooder's instrumental music is for closing your eyes and taking a trip. Let the walking-pace melody lead you, let each mournful yet menacing note build you a character from a John Ford western or a Jim Jarmusch fable. Whatever happens in your daydream, you'll not be wanting for atmosphere.