DON: You got anymore little chores you want done in this picture?
Here, Don's talking to Dexter after taking the punch that jumpstarts his career as a stuntman. It shows that, before he was a star, Don was all about adapting and rolling with the punches (sometimes literally) in order to get where he wanted to go professionally.
MAN IN TALKING PICTURES DEMONSTRATION: Hello! This is a demonstration of a talking picture. Notice, it is a picture of me and I am talking. Note how my lips and the sound issuing from them are synchronized together in perfect unison.
If it sounds like the man in the talkie demo is speaking to the audience like they're a bunch of five-year-olds, it's because he is. The technology was super-new. That explains his demo approach as well as the audience's confusion and disbelief that, to modern audiences, seems silly.
ROD: R.F., do you think they'll ever really use it?
R.F.: I doubt it. The Warner brothers are making a whole talking picture with this gadget, The Jazz Singer. They'll lose their shirts. What do you think of it, Dexter?
DEXTER: It'll never amount to a thing.
COSMO: That's what they said about the horseless carriage.
It's pretty interesting that R.F. and Dexter, two of the most powerful men at the studio, are suspicious of change here. Meanwhile, piano-playing Cosmo is looking to the future.
COSMO: Why bother to shoot this film? Why not release the old one under a new title? You've seen one, you've seen them all.
DON: Hey, what'd you say that for?
COSMO: What's the matter?
DON: That's what that Kathy Selden said to me that night.
COSMO: That's three weeks ago, you still thinking about that?
DON: I can't get her out of my mind.
COSMO: How could you—she's the first dame who hasn't fallen for your line since you were four.
Two things worth noting here: First, Cosmo's attitude reveals how resistant to change and downright lazy the studio's become. Second, it's not just Don's job that's changing; his love life and his romantic priorities are, too.
COSMO: What's the first thing an actor learns? "The show must go on!' Come rain, come shine, come snow, come sleet, the show MUST go on!
"The show must go on" is just a fancy way of saying that, no matter what, you have to adapt. Or, as they say in the business world, "Change or die!"
COSMO: Talking picture? Well, that means I'm out of a job. At last I can start suffering and write that symphony.
R.F.: You're not out of a job. We're putting you in as head of the new music department.
COSMO: Well, thanks, R.F.! At last I can stop suffering and write that symphony.
No matter what happens, Cosmo's going to roll with it.
DEXTER: Now wait a second, Mr. Simpson. Talking pictures. I think you should—
R.F.: Every studio's jumping on the bandwagon, Dexter. All the theaters are putting in sound equipment. We don't want to be left out of it.
DON: We don't know anything about this gadget.
R.F.: What do you have to know? It's a picture. You do what you always did? You just add talking.
R.F.'s attitude toward talkies changes over the course of the film. Why do you think that is?
DEXTER: Lina! We're missing every other word! You've got to talk into the mike!
LINA: (pointing at the bush where the microphone is hidden) Well, I can't make love to a bush!
Either Lina's resistant to change, or she's just not a very good actress. Talkies required a whole new skill set.
DON: Once they release The Dueling Cavalier, Lockwood and Lamont are through. The picture's a museum piece. I'm a museum piece.
Don's first reaction to the onslaught of sound is to roll over and die. Good thing he's got Cosmo and Kathy in his corner.
KATHY: When we left the movie show / The future wasn't bright / But came the dawn / The show goes on / And I don't wanna say good night
DON AND COSMO: So say Good Mornin'!
Don's mood does a 180 when Cosmo comes up with the idea to turn The Dueling Cavalier into a musical that can draw on Don's skills from his old vaudeville days. See? This is why Don's lucky to have Cosmo. He should buy him a fruit basket, or maybe a new tire.
DON: I'm singing in the rain / Just singing in the rain / What a glorious feelin' / I'm happy again / I'm laughing at clouds / So dark up above / The sun's in my heart / And I'm ready for love
Falling in love with Kathy sure does wonders for Don's willingness to change.