You can read the 2400 word essay I posted yesterday about D.W. Griffith's development of a film "language" and how he taught every director from Charlie Chaplin to Christopher Nolan how to manipulate an audience's emotions, or you can watch this 49-second clip from 30 Rock, which pretty much covers the same territory. Your call.
(You can watch the entire episode here at Hulu.)
Alternate Best Supporting Actor 1990
34 minutes ago