I happened to write down from memory most of a Jerry Seinfeld visit to David Letterman's show (last May). Jerry teaches David about comedy acting. (I don't know how well it translates in print.)
------ Before first commercial break, Dave stops and tells viewers: "You know, we don't ask you to *patronize* the businesses that advertise on our show. [pause] Just sit back and enjoy the colorful images." [freezes a pleasant smile]
Seinfeld is visiting, talking about his show. "Dave, you can act as well as these other comedians with their own TV shows. [...] Get on that acting gravy train, Dave. Milk that cash cow." He's going to teach Dave the secrets of Comedy Acting.
By the desk, they have a little TV. Seinfeld shows a scene of him in his apartment, talking to Kramer:
Jerry: "This is the best lock made! It only has *one* fatal flaw! The DOOR - has to be: SHUT!!!" [he's slamming door during end]
Picture is frozen and Seinfeld has this pencil that draws right on the phosphur of the little screen.
S: See Dave, [draws arrow to illustrate door shutting] *this* motion is Comedy Acting. And see him? He looks *confused* [draws question mark above Kramer's head]. And this is what you get [writes "Ha!" in the middle of screen]: Big Laughs.
DL: Wait a minute.. so *this* motion, shutting the door..
S: Yes, *this* *motion* [draws a second door arrow] *creates* Comedy. You do this, you create Big Laughs, Dave.
DL: [like a student who's not sure he's got it] Wow. So let's take a look at the next one.
Seinfeld clears the screen of the phosphur lines and shows the next scene.
In kitchen: Seinfeld has a golf club or pool cue in his hand and is talking to Kramer and George, who are right by the refrigerator. Kramer is closer to Jerry than George. I couldn't hear the dialog. Seinfeld lifts the end of the whatever and aims it like a pool cue up at Kramer's head. Kramer stays in the same place but his head sort of slides away before the end of the stick. George also stays in his position, but slides his head away and down because Kramer's head is in the way. They both look mildly alarmed.
The scene freezes.
S: Big laughs. Now, see, Dave, I move the pool cue this way. And Kramer has to move his head out of the way so he won't get hit [draws arrow of movement by head]. And, LOOK. *He* has to move his head a little to get out of *his* way [draws a little arrow downward next to George's head]. And there's your laugh [writes "Ha" on screen]. See, I move the pool cue this way, and they move their heads this way and this way [now he's using the pencil without drawing on the screen]. Now Dave, this causes Big Laughs.
DL: [like he's learning] Oh .. I .. see. What you've done here is you've created a Comedy *VORTEX* [excited, uses hands to parallel the two arrows].
S: [laughs] *Yes*. You're catching on.
S clears screen of the phosphur lines and shows next scene. In it, he's sitting on his kitchen counter island, holding a bowl of cereal in one hand, the spoon in another, while saying something to someone just off-camera. The scene is frozen there.
S: Ok. What do we have here. [circles bowl] We have this. [circles spoon] And this. Now what is going on here? I'm eating a bowl of cereal during the show. What is this: I was so hungry, I couldn't wait until after the show to eat? [waits a moment] No. *This* is Comedy Acting. I didn't have to eat cereal during the show, but Dave, this CREATES comedy. Big laughs. If I wasn't holding that bowl of cereal, it wouldn't be Comedy Acting.
DL: Yee-es! Well, thank you very much!
S: Certainly.