- The 1963 March on Washington for jobs and freedom, would be a showcase for sermon and song.

The day's program packed, King had been allotted only a few minutes to deliver his remarks.

Those remarks would turn out to be the speech of a lifetime, and as always, Mahalia was there to lift him up.

♪ I've been buked ♪ ♪ And I've been scorned ♪ - "I've Been 'Buked and I've Been Scorned," is an honest to God deep, deep spiritual.

It would've been known by the great majority of the people there.

(Mahalia holding a tune) She sings it in her most dramatic Baptist surge, singing, stretching it out, and it becomes almost magisterial, (continues to sing "I Been 'Buked and I Been Scorned.")

And she is hypnotizing.

- That moment at the March on Washington, where she's singing before King speaks, is kind of a moment of transfer that you might see in a Black church.

You often get a song just before the minister comes up.

- I am happy to join with you today in what will go down in history as the greatest demonstration for freedom in the history of our nation.

(crowd cheers) - He had a prepared speech, and he goes on to talk about the particular failure of the United States for Black people.

I mean, he's real clear on that.

- Scanning the crowd from behind, Mahalia noticed that the throngs of marchers stretched along the Mall seemed to be getting restless.

- Sitting behind him over one shoulder, she's watching the crowd.

Because that's what Mahalia does.

And she sees that that cadence, that power that she had seen earlier in Detroit, isn't there.

And that's when she says, "Tell 'em about the dream, Martin.

Tell 'em about the dream."

And coming from anybody else, it might've, it might've thrown him off his cadence, but it doesn't.

He pivots in mid-sentence, and then moves like the the great Black preachers that he has heard, and begins with this rhythmic cadence, this songlike incantation, that becomes one of the great speeches in American history.