Sullivan's Travels (1941 Preston Sturges & scr)

That opening sequence runs from 2:51 to 6:41. It's a marvellous single take, absolutely perfectly performed by (left to right) Joel McCrae, Robert Warwick and Porter Hall, very funny of course, and because of characters moving in and out of shot, very like an early Woody Allen scene:

The changing portrait is absolutely inspired, so subtle and clever:

Is interesting in that the last third is quite serious, thus perhaps why some critics (such as Derek Malcolm) rate this as his best.

Rest of cast Veronica Lake, Eric Blore, Robert Greig, William Demarest, Byron Foulger, Franklin Pangborn, Margaret Hayes, Charles Moore and Jimmy Conlin, superbly shot by John Seitz.