The Martin Luther King Jr. Day in the United States reminded me of this great podcast episode on improvisation in public speaking. King was a fantastic orator who was meticulous in preparing speeches and sermons.

“King lavished enormous efforts on his sermons. He would begin drafting on a Tuesday and continued to research and draft throughout the week, drawing inspiration from Plato, Aquinas, Freud, and Gandhi. As Sunday approached, he would write it all out in yellow-lined paper and commit it to memory. He would bring the script to church with him but as he ascended to the pulpit, he would leave it on his chair and speak without notes for half an hour or more,” said Tim Hartford in his podcast Cautionary Tales.

King, Hartford said in his podcast that you should follow, “assured that every syllable of his oratory was meticulously prepared.”

It was when he was pressed for time that he realized the power of improvisation. This was when he was forced to immediately speak after Rosa Parks’ arrest. He had only 20 minutes to prepare and he was “possessed by fear.”

“He understood what older preachers told him, open your mouth and God will speak for you,” Hartford said.

Hartford said brain studies show that the “improvising brain is disinhibited.” “Improvisers shut down their inner critics.”

More than 7 years later, King was at the Lincoln Memorial giving a speech during the March on Washington for Jobs and Freedom. His script was titled, “Normalcy, Never Again.”

“Normalcy never again was over-formal and flawed. As he read out the speech it did not stir the soul,” Hartford said. Towards the end, he skipped a “pretentious and limp” ending. Singer Mahalia Jackson yelled, “Tell them about the dream, Martin!”

Martin, according to Hartford, heard Mahalia and created on the fly one of the most historic speeches of the 20th century.

We know it today as the “I have a Dream” speech.