Night Mail is a 1936 documentary film about a London, Midland and Scottish Railway (LMS) mail train from London to Scotland, produced by the GPO Film Unit. A poem by English poet W. H. Auden was specially written for it, used in the closing few minutes, as was music by Benjamin Britten.
It's been updated with a 21st Century groove by London duo Public Service Broadcasting
Night Mail - Public Service Broadcasting from PSBHQ on Vimeo.
If the above video doesn't work... try this:
Sources:
Cool Cards blog - Night Mail
Public Service Broadcasting