The word itself is of North Indian Origin. A dictionary of Hindustani terms describes it as a court of law, a place of decision making and also a congregation of people. In early time, justice was meted out by a collective vote and so the various meanings loosely stand for a collection of people who pass judgement. Now how does this fit in to the Carnatic Music concert? Firstly, it is a trail of skills for any artiste. Secondly the audience does pass judgement on the performer depending on how well he presents his art. Thirdly, a large part of the concert is a musical argument, an exchange of notes, between the main performer and his accompanists. The audience judges them on these arguments. Lastly, most concerts in days gone by used to take place in the presence of the local chieftain who also held the responsibility of law and rough justice. So the term Kutcheri came to describe a concert also.
The Kutcheri as we know it has undergone many mutations. In the early days, it was more raga oriented. In fact a single raga oriented. Musician would begin with a varnam and then proceed to the main raga which would be elaborately dealt with Legend has it that such raga expansions could last for many days. Later, with time becoming a crucial factor as also audience tastes that demanded variety, the format changed.
Ariyakkudi Ramanuja Iyegar, a doyen in the Carnatic world, is credited with the current format. This starts with a varnam, followed by a piece of Ganesha. Then there are short raga alapanas, followed by kritis, some of which are rendered with neraval (imaginative declamations of a single line in the same raga) and swaras. This is then followed by a raga dealt with expansively succeeded by tanam (rendering the raga in medium tempo, with the syllables anantam) and pallavi. The pallavi is a single line set to a tala, which is rendered in various ways without crossing the boundaried of the raga. The pallavi is followed by a few short pieces in light ragas and the mangalam (invocation of all that is auspicious) is rendered. This ends a kutcheri.
But long after it is over, it lingers in the minds of the audience which ruminated and reflects over it and passes judgement on it. This judgement is often held up as a standard in comparing other performances of the same musician or of other musicians. The analogy with courts and low continues...