Music is an inseparable part of Indian theatre. Vocal music or Sangita includes gita (vocal music), vadya (instrumental music), and nartana (dancing) and depends upon rhythm. In the art of music there are two main distinctions in the theory and practice of Sangita. They are recognised by the names Marga (high style), and Desi (popular style). Marga sangita (gandharva or celestial music) was employed by the celestial musicians or by sages who knew the theory of sacred music. Desi sangita (terrestrial music) varies from country to country according to the taste of the people of a particular region and is a source of pleasure. Music is the accessory art of Indian theatre and helps to develop the grandeur of the play.

The sound of music is called nada, intelligible sound, and is said to have resulted from the union of physical breath with the fire of intellect. According to the Indian theory, the sound of music are first perceived as relative pitches or intervals and then from the twenty two main intervals or srutis come the seven notes or svaras which are sadja, rasabha, gandhara, madhyama, pancama, dhaivata and nisada. The sound that generates an expression is called a svara or a note. Bharata in his Natyashastra divides svaras into four kinds according to the number of srutis between them, which are vadi (sonant), samvadi (consonant), anuvadi (assonant) and vivadi (dissonant). A combination of svaras is called grama. The three svaras (notes) namely udatta (raised), anudatta (not raised) and svarita (circumflex) of the Veda are not included in the grama. Sadja grama is the best of all the gramas. Ragas (modes) are mainly produced from sadja grama. Raga is the basis of melody in Indian music.

Music was an indispensable adjunct of Indian theatre. Theorists state that each sentiment has its appropriate music and each action its special accompaniment. Usually the Sanskrit drama begins with music and ends with it. Even during the enactment of play, there are various references to the music performed. In the play Ratnavali, two maids sing dvipadikhanda before the king. In the play Malavikagnimitra, the character of Malavika sings and acts. In the play Mricchakatika, Carudatta goes to attend a musical concert and while returning explains the beauty of the song of Rebhila to his associate Maitreya. Music was an inseparable part of Indian theatre. Dramatic songs pre eminently were dhruvas having varna, alankara, tempo, jati and pani in a systematic manner. Dhruvas had five classes namely pravesiki, aksepiki, naiskramiki, prasadiki and antara based on occasions and suggesting respectively entrance (pravesta), turning aside (aksepa), departure (niskrama), countenance (prasada) and transition (antara) in the course of the development of plots of different plays.

Pravesiki dhruvas were sung at the entrance of the characters on the stage taking into reflection short dissertations of diverse sentiments. Aksepiki dhruva were sung when a new sentiment is brought to rise having subdued the one already present. Occasions where one is being obstructed, fallen, or afflicted with illness aksepiki dhruvas were sung. Naiskramiki dhruva songs were sung at the exit of characters to show their going out of the stage. Prasadiki dhruvas were sung for bringing solace to the audience after they witnessed something which agitated their feeling very much. Antara dhruvas were sung by adopting a quick tempo in place of medium or slow tempo to redirect the attention of the audience at a time when chief characters become ominous, absent minded, angry, intoxicated, or lose consciousness. Dhruvas were a kind of background music based on the contents of the songs, their metres, language, tempo and tala, suggesting acts and moods of different characters in a play. Dhruvas are considered to be the vital life of dramatic performance. The song sung by Malavika in the beginning of the second act of Malavikagnimitra was a dhruva song. The particular dhruva sung by Malavika can be of prasadiki type as it was adjusted to madhya tala and was sung to intensify the appeal of sringara rasa. In the first act of Nagananda, the song sung by Malayavati, shows that dhruvas were sung on the stage by the main characters of the drama.

Instrumental music also has a major role to play in Indian theatre. In India there are four kinds of musical instruments. They are stringed instruments; wind instruments, drums and cymbals, bells and gongs. The Natyashastra states that tatam comes under the category of stringed musical instruments, susira under wind instruments and avanadham under instruments of percussion like drums and ghanam (solid) instruments (cymbals) which are struck against each other. Ancient Sanskrit treatises and Indian sculpture illustrate musical instruments in detail. Orchestra in ancient plays served a definite dramatic purpose. Temples have played a great part in the preservation of musical instruments. Dramatic poses as described in the Natyashastra are found sculptured on the walls of the Nataraja temple at Chidambaram showing some musical instruments. At Ajanta also there is a painting representing the dance intended to allure Mahajanaka. The orchestra there comprises five artistes, two of them playing cymbals, one a pair of drums, another mridanga and the fifth apparently a guitar. Two women playing the flute are also found in the painting. In India there are nearly four hundred musical instruments each with a distinct name, shape and quality of tone. In Natyashastra there are reference of musical instruments such as mridanga, panava, dardura, dundubhi, muraja, jhallari, pataha, vamsa, sankha and dakkini.

Thus music plays a vital role when it comes to Indian theatre. Accompanied with orchestra and instrumental music, this accessory art of Indian theatre enhance the beauty and grandeur of the play.