Trinidad & Tobago EXTEMPO Calypso

Extempo (also Extempo Calypso) is a lyrically improvised form of Calypso and is most notably practised in Trinidad and Tobago. It consists of a performer improvising in song or in rhythmic speech on a given theme before an audience who themselves take turns to perform. It is inherently competitive and success is judged by the wit and ingenuity of the performance.
It is similar in form to what has been defined as traditional African song: “a recitative or chants with a short chorus. The soloist gives the melody while a chorus sings a refrain. As the melody is given out, they turn to one another, each improvising in turn. Extempo tends to comprise topics from current events treated with mockery, ridicule and sarcasm, or with flattery or praise.”
Extempo war
The competitive nature of extempo is reflected in the annual Trinidad Carnival with a formal extempo competition for the title of National Extempo Monarch. Extempo War, or warring, is the practise of competitors attacking each others efforts at extempo in the course of their own performance. It is not an essential part of competition, but is a regular feature, and an entertaining one. Extempo war may also be called simply Calypso War. (From Wikipedia)