A classic from the NFB called "The City". Just be aware there is a couple of minutes of darkscreen video while the music is grooving off the top. If you can't live with that, skip ahead. From the www.nfb.ca website description:
An animated fantasy that shows Canadians as urbanized people developing a vast wilderness with the aid of the latest technologies. Shown as part of the Urban Environment exhibit in the Canadian pavilion at the international exposition, Osaka '70.