The anticipatory period leading up to a performance of any sort is difficult for most performers, but there is a particular challenge involved in waiting to perform an act that is to some degree extemporaneous, and battle rap is a rather harrowing mix of the extemporaneous and premeditated.

FORBES: Behind the Scenes at World Domination II, Part One

Her hours-long lecture is a mesmerizing romp of set pieces and extemporaneous patter, jumping from Christopher Columbus, to Egyptian pyramids, to the Great Wall, to Bill Gates.

WSJ: Inside the Amway Sales Machine

Certainly a great deal of preparation goes into a debate performance, but most of what a politician says up there on the stage is extemporaneous.

CNN: 'The Bush Dyslexicon' author Mark Crispin Miller

The 88-page quarterly, which calls itself GR for short, serves up a "punk-rock" sensibility that borders on extemporaneous.

CNN: Raw, Original and Truthful

He was a person who took care to leave his speeches and sermons open to extemporaneous remarks.

NPR: The Significance of MLK's Personal Papers