Fun fact I learned recently about film background crowd noise.

[brush]

In American radio, film, television, and video games, walla is a sound effect imitating the murmur of a crowd in the background (walla walla).

https://en.wikipedia.org/wiki/Walla

[Ocelot II]

1. I thought it was rhubarb rhubarb rhubarb?

[DBoon]

2. I was told it was "peas and carrots"

[brush]

3. In the UK it is rhubarb over and over. That's in the link.

[Leghorn21]

4. I was told it's "rhubahbs and gahbage"!!

A regional thing, perhaps!

[captain queeg]

5. I read a few years ago that there was only one source for laugh tracks

Don’t know if that is still true.

[Hoyt]

6. Sort of like more cowbell.

[brush]

7. Not quite. But I'm a huge Christopher Walken fan.

He's not only an actor but a terrific hoofer. I'm sure since you've seen the "more cowbell" video, you've seen this Fatboy Slim, "Weapon of Choice" one.

[left-of-center2012]

8. Sound effects are a large part of movie making

There is or used to be a museum in Hollywood that showed you how they made the sound effects.