Send in the Clowns - clarification

Send in the Clowns:
Version I: As sung by Barabara Streisand
Isn't it rich, are we a pair?
Me here at last on the ground,
You in mid-air.
Send in the clowns.

Isn't it bliss, don't you approve?
One who keeps tearing around
One who can't move
Where are the clowns?
Send in the clowns.

Just when I'd stopped opening doors,
Finally knowing the one that I wanted was yours.
Making my entrance again with my usual flair,
Sure of my lines;
No one is there.

Don't you love farce?
My fault I fear,
I thought that you'd want what I want,
Sorry my dear
But where are the clowns
There ought to be clowns
Quick send in the clowns

What a surprise!
Who could foresee
I'd come to feel about you
What you felt about me?
Why only now when I see
That you've drifted away?
What a surprise...
What a cliche'...

Isn't it rich, isn't it queer
Losing my timing this late in my career
And where are the clowns
Quick send in the clowns
Don't bother, they're here.

Hey ward

I really dont know what your question is or what you want to discuss, but if you wish to write back and tell me I may be able to help you.

My question was lost in cyberspace! This phrase, memorialized in the famous Steven Sondheim song, is supposed to be of carnival or circus origin. It relates in some way to the practice of sending in the clowns to divert the attention of the audience when some tragedy or mishap occurs.
Can anyone shed some light on the origin of the phrase, and the detail of its meaning?