This (short) video by MC78 has a gorgeous visual style.
In the Adda's river valley in Italy, old legends tells about the " Days of blackbird" (last days of January); this days are the colder days of the year. A long time ago blackbirds were white but they found shelter in a chimney from which hot and black smoke came out. Since those days of late January the blackbirds are black.
This 3d animation is part of a documentary about Adda's river.