Heat Waves in a Swamp: The Paintings of Charles Burchfield. "Burchfield’s primary subject was landscape, often focusing on his immediate surroundings: his garden, the views from his windows, snow turning to slush, the sounds of insects and bells and vibrating telephone lines, deep ravines, sudden atmospheric changes, the experience of entering a forest at dusk, to name but a few. He often imbued these subjects with highly expressionistic light, creating at times a clear-eyed depiction of the world and, at other times, a unique mystical and visionary experience of nature." I recommend the slide show in the first link as the best introduction. More audio slide shows from Peter Schjeldahl here.