Orchestration and Purpose of Indian Kathakali


Indian music has a tight bond between melody and rhythm. These two, similar to Western music, provide the structure. The music is based upon ragas, which are tonal patterns in which a piece of music is set. It is similar to a scale, and has a tonic to which the music gravitates, however the interval patterns in ragas are different than those in a western scale. The music also works in quarter tones, and from tonic to tonic there are 22 intervals called “sruti”. These can be recombined into groups of twelve semitones called “swara”, which is the basic movement of Indian music. Below is a diagram outlining the division of Indian notes relative to other scales, as well as the solfeggio they use to identify the scale degrees.
http://www.oocities.org/drbobsmithau/india/indmuz6.htm

Indian music has about 130 ragas that are used, though some are more popular than others.
Kathakali strongly relies on musical structure to propel the theatrics. The orchestration is quite light, with the focus being kept on the singers harmonizing with one another. Drums are used to help maintain the tempo and set the rhythm, with the chengila (like cymbals) and the chenda (drum) being two of the most popular percussion instruments. While some wind and string instruments provide some background music, the vocals and the percussion are the main instruments of Kathakali. 
Kathakali is very intensely focused on relaying the story through the dancing, acting, singing, and persona as a whole. The story is often in what is left unsaid, which is why the technique is so prized, and this ideal is described as "Where the hand moves, the eyes follow. Where the eyes move, the mind follows. Where the mind moves, the mood follows. Where the mood goes, there the Rasa [flavour] arises," (Vijayakumar).
Kathakali follows basic plot structure, and tells stories of religion, folktales, and history. There are six basic character types, which are Pacha, Katti, Tadi (evil), Tadi (pure), Katalan, Minnikku, and Narasymham, and these represent heroes, evils, fantasy, females, and sidekicks, all to further the plot and tell the story. Ultimately, Kathakali takes "story telling into the heart of the people through total theatre," (Vijayakumar).