The phrase "unscripted speech" is correct and usable in written English.
It can be used to describe a speech or talk that is delivered without a prepared script, often allowing for spontaneity and natural expression.
Example: "The politician's unscripted speech resonated with the audience, showcasing his genuine passion for the issues at hand."
Alternatives: "improvised speech" or "spontaneous speech".
Trump's unscripted speech reportedly caught senior White House aides by surprise.
In a largely unscripted speech he said the party would become more "inclusive, more involved, more democratic" and would "shape the future of everyone in this country".
Klein's new book, Politics Lost, opens with a stirringly dramatic unscripted speech given by Bobby Kennedy on the death of Martin Luther King.
Between performances of her poetry at the Roslyn Packer Theatre in Walsh Bay on Tuesday evening, Tempest delivered an unscripted speech about empathy, history, politics and the importance of storytelling.
If the text is a transcript of unscripted speech, or is written to reflect patterns of speech, it will be constructed with units of information that match patterns of spoken English.
In the course of an hour's unscripted speech, he mercilessly ridiculed Mr Zuma for the tax-payers' millions spent on upgrading his private home, and said Nelson Mandela would be spinning in his grave if he could see what the governing African National Congress (ANC) had become, and how a corrupt, narrow elite was profiting at the expense of a marginalised black majority.
A large part of the appeal of an awards show is watching for celebrity gaffes and unscripted speeches.
As they have appeared together, in theaters and town halls, Mr. Blair has presented himself in shirt-sleeves, delivering his message in unscripted speeches.
In fact, his unscripted speeches were so popular that thousands of people would pay to hear him speak – at a time when most politicians had to bribe their audience with free drinks, food and gifts.
The conference slogan will be "Straight talking, honest politics" – an echo of the Corbyn leadership campaign in which he shunned razzmatazz in favour of hundreds of unrehearsed and often unscripted speeches.
Trump's rallies represent, of course, the first of these; so do his unscripted speeches, which barrel, like a truck without brakes, into a ditch, wheels still spinning, kicking up gravel.
