'Kalasam' is a dance sequence (pure dance passage) in which classical dance?

The correct answer is Kathakali. In Kathakali, the classical dance-drama of Kerala, a kalasam is a passage of pure dance (nritta) performed by an actor, usually at the end of a section of a song or a scene. Kalasams are used to mark the completion of a phrase, to emphasise an emotion or a dramatic moment, and to give the actor a chance to display skill in rhythm and movement.

There are many kinds of kalasams, which differ in their speed, length and style, and they are performed to the beat of the chenda and maddalam (drums). They often come at the end of each charanam (verse) of a padam (song), after the actor has acted out the meaning of the words through mudras and facial expressions. Kalasams help to give rhythm and structure to the long performances of Kathakali, which traditionally last through the night. The vigorous kalasams of the male characters reflect the tandava style of Kathakali, which is a demanding, energetic dance-drama.

A Kathakali performance follows a set order. It begins with the Kelikottu, the beating of drums in the evening to announce the performance, followed by the Arangukeli, the Thodayam (a prayer performed behind a curtain), the Purappadu (the entry of the characters), the Melappadam (a musical interlude) and then the main story. The performance usually ends with a Dhanashi, a closing prayer. The stories are taken from the Ramayana, the Mahabharata and the Puranas, and the texts, called attakathas, are written in Manipravalam (a mix of Malayalam and Sanskrit).

About the other options:

• Bharatanatyam uses pure dance passages called jathis and adavus, and items such as Alarippu, Jatiswaram and Tillana.
• Kuchipudi uses jathis and items such as the Tarangam.
• Sattriya has its own types of dance, such as Chali, Jhumura and Nadu Bhangi.