"Let's get started" vs. "Let's get it started"

[GoodTaste]

Is the phrase "Let's get started" the shorter form of "Let's get it started"?

That is, the former is more colloquial.

 

[GoodTaste]

Are they different in meaning?
What difference?

 

[GoesStation]

"Let's get started" = Let's start doing something we've been discussing.

"Let's get it started" = Let's start the thing we've been talking about.

The object pronoun in the second sentence means you're acting on something other than yourselves.