One of the most famous speeches of the 20th century was very nearly something quite different. When most of us think of the speech that Martin Luther King, Jr. gave at the 1963 March on Washington for Jobs and Freedom, we call to mind only the final third of the address that begins with the resounding “I have a dream” sequence. The first eleven minutes or so, while captivating to hear, read, or watch, are not nearly as powerful or memorable as the final five and one-half minutes.

In his book Behind the Dream: The Making of the Speech that Transformed a Nation, Clarence B. Jones, advisor to King and co-writer of the speech, explains that King delivered the first part of the address as it had been prepared and rehearsed. If you watch the delivery, you will notice King’s looking down at his notes quite often. It takes him awhile to find his cadence, but even when he does, he is reading rather than speaking extemporaneously.

Then, as Jones writes, in the pause that follows “We cannot turn back,” gospel singer Mahalia Jackson shouted “‘Tell ’em about the’Dream,’ Martin, tell ’em about the ‘Dream!'”

While King continued with his prepared words for several seconds, Jones saw and heard his friend prepare to change course:

“I leaned over and said to the person standing next to me, ‘These people out there today don’t know it yet, but they’re about ready to go to church.’ From his body language and the tone in his voice, I knew Martin was about to transform into the superb Baptist preacher he was; like the three generations of Baptist preachers before him in his family.

Then, honoring Mahalia’s request, Martin spoke those words that in retrospect feel destined to ring out that day:

I have a dream . . .”

Being able to change perspective and direction, even and perhaps especially when the stakes are high, is one of the hallmarks of creative thought. You can read an excerpt from and listen to Jones discuss the book at NPR’s Fresh Air. Watch the full speech below and notice that after the 12:00 mark, King no longer refers to his manuscript as he connects forever with his audience and history.