One second of a classic Looney Tunes short story.

This compilation, One Second from Every Classic Looney Tunes Short, is fairly self-explanatory.

Interesting in its own right, it is also a valuable tool for studying the changing styles of Hollywood animation from the early 1930s through the 1960s.

Try making a similar compilation of long-running contemporary shows, such as The Simpsons, and you will see that the graphic evolution is not so dramatic or interesting. In modern animation, the idea of evolving the visuals is forbidden. The goal is to settle on a definitive style within the first few seasons, as this will make merchandising and licensing programs easier to implement.

It is not certain what the studios gain by eliminating the incentive for artists to experiment and evolve their artistic skills, but it is certainly clear from this video what is lost.