Music is one of the oldest and finest forms of human expression. The Vedas, representing the most ancient literature known to the world, are set to a distinctive melody, that has been passed down through the centuries in an unbroken oral tradition.
Being an abstract art form there are many definitions given to music. Emotional and scientific correlation of sound in space and time is a safe definition of music. 
Music is a painting drawn with invisible lines and colours of sound on the canvas of silence. Music is like an inexhaustive spring and infinite space. There is music in cosmic breath. The waves of oceans, the embrace of bamboo branches, vibrations of atoms and heartbeats: music is omnipresent.
However, music has evolved as a definite art form during the childhood of human civilization in folk music. The agony, ecstasy and anxiety of life, meandering and fascination of nature, desire and hope for a fruitful future, all get its forceful expression in different art forms and music in particular.
Every near perfect expression of classical music stream is nothing but diamonds and emeralds emerged out of far different material chiselled by time.
Music can be divided into Western classical, Hindustani classical, Carnatic classical, folk, Jazz, Pop, Fusion, etc. Of these there can be further identification of Vocal and Instrumental music. Within instrumental there can be differentiation of percussive instruments as well as wind and string instruments.
In India, the arts have been classified by the scriptures into two major streams known as margi and desi that can be roughly translated as classical and folk. Numerous texts such as the Sangeeta Ratnakara of Saarangadeva lay down the basic tenets of classical music.
The two major systems of classical music today are the Hindustani and the Carnatic. Though today they appear to be quite distinct styles, they in fact have their origins in a common theory and source as is apparent from ancient treatises.
Kathakali Music
The orchestra is formed of two varieties of drums - the maddalam and chenda; the chengila which is a bell metal gong and the ilathalam or cymbals.
Murpancharimelam / Pandimelam
It is the traditional temple percussion music. 

Panchavadyam (Literally five Instruments)
It is traditioanl temple music accompanying processions and pegeants. The five instruments are Chenda, Kuzhal, Edakka, Elathalam, Timila.
The Thiruvathirappattu, a song typical to Kerala which has got many varieties, is a reminder of the days when Thiruvathira was observed as an occasion to celebrate womanhood. The song accompanies Thiruvathirakali, a dance performed by women for everlasting marital bliss, on the Thiruvathira asterism of the Malayalam month of Dhanu (December/January).
The sinuous movements executed by the dancers around a nilavilakku (the traditional oil-lit wick lamp made of brass) embody lasya or the amorous feminine charm and grace. The dance follows a circular, pirouetting pattern accompanied by clapping and singing.
This Thiruvathirappattu beginning " Gopala balakanae gopikakanda..." is an ancient song with a devotional tone and describes the romantic tales of Lord Krishna.
'Villadichanpattu' literally means a song sung to the strumming of the villu (a big bow with a tout string). This ancient ritual art form, with much prominence for its music, is more prevalent in parts of Thiruvananthapuram district. The themes are based on mythology and are presented either during the day or at night. The duration of a performance varies with that of the story.
At least five people are needed for a presentation. Villu (bow), sukol, jalar, pot (percussion), visari and dholak (a percussion) are the musical instruments used by the performers.
The performers wear a dhoti around the loin, a cloth tied around the temple and a kuri (a mark on the forehead using sandalwood paste). The settings required are a nilavilakku (wick lamp) and the pooja (worship) articles required for Ganapathi pooja.
Much before codified music was known to mankind, Vedic recitations or chantings were the only music found in the Indian subcontinent. It is thus believed that this unique style of Vedic chanting called 'Swarikkal' is the prototype of 'raga' and 'thala'. The Vedic chantings or Swarikkal had the characteristics of a typical raga as well as prose reading.
In Kerala, Swarikkal was used in Kootiyattom one of the oldest performing art of the land. Till today not much changes have crept into this. The Swarikkal in Kootiyattom are a few among the forerunners of Sopana Sangeetham, supposed to be the most ancient music of Kerala.
This music clip has a Swarikkal that is the Peedika of Kootiyattom - the initial invocation. The Peedika is in praise of Sri Rama, as the story following it is from the epic Ramayana. Though it takes its themes from the epics, Kootiyattom is an 'open' artform, as the character Vidhushakan (the wise man) enjoys all the freedom to criticise any topic of any age or time.
Yet, for this subtle art of criticism he requires the blessings of goddess Saraswathy, the goddess of vidya (knowledge). Through the Peedika the artiste also seeks the blessings of Lord Ganesha who is believed to be the remover of Vignas (interruptions).
Peedika also speaks about the significance of Koothu or Kootiyattom performance. It says that each human life is a god given gift and one way to utilise it to the optimum and achieve salvation is by listening to Sathkatha or moral stories, which is possible through the presentation of Kootiyattom.
Sarpa Pattu
Sarpa pattu (Sarpam thullal) or snake dance is a ritual art performed in shrines and temples devoted to Nagaraja the king of serpents. It is performed by women who belong to the Pulluvar caste, in a specially decorated pandal, before the sarpakalam (snake designs on the floor). The women dance in a frenzy to the rhythm of the sarpa pattu, until they fall down exhausted. The sarpa pattu is performed to the accompaniment of veena, kudom and kaimani.
Musical instruments used in temple
Chenda, Maddalam, Udukku, Thakil, Veekuchenda, Timila, Ganjira, Edakka, Thudi, Kuzhal ( horn), Elathalam(small Cymball), Chengila (bronze gong), Chaplankatta (a wooden device struck together using the fingers), Nagaswaram (Long Horn ), Mizhavu ( a large copper pot), Nanthuni ( Instrument similar to the veena)