A new form of Hindustani classical emerged during the 13th and 14th centuries. This was known as 'Khayal' meaning 'imagination'. The style gave an entirely new meaning to Hindustani classical music. Amir Khusrau is considered to be the proponent of this style.  

'Raga' meaning 'melody' is India's contribution to the world of music. It is fundamental to Indian classical music, both Hindustani and Carnatic. A highly scientific and practical manner for the classification of raga was introduced by Venkatamahi. This became the foundation for Indian classical music. Ragas are made of different combinations of 'sapta swara or seven notes'. These are Sa- Sadjam, Ri-Rishabam, Ga-Gaandhaaram, Ma-Madhyamam, Pa-Pancham, Dha-Dhaivadam, Ni-Nishadam. 

In western classical music, the Piano has an octave that consists of 12 notes, whereas in Indian classical music the same consists of 22 notes or shrutis. Swara is generally defined as a note whereas a shruti is the microtonal intervals between two swaras. 

The great diversity of Indian traditions has given birth to a variety of musical instruments. Some of these instruments are played solo while others are used as accompanying instruments to the soloists and  dancers. There are instruments that are strictly devotional and ritualistic like the conch and the Khol drum. The evolution of most musical instruments is evident in the ancient cave paintings and sculptures of historic temples. Indian musical instruments are also broadly classified into the four types: stringed, wind, percussion and bells, cymbals and gongs.  

The stringed instruments vary according to their complications. The simplest of these being, the single stringed 'ektara'. The veena, sitar, sarangi and sarod too are popular stringed instruments. These instruments commonly have round resonators at one end and are made  out of dried hollow gourd. The veena is said to have been used by Bharata in his musical studies. The sitar is said to have been invented by Amir Khusrau. The sarod is smaller of the lot and has 10 main strings and 15 sympathetic strings. The sarangi on the other hand, is played with a bow. The other stringed instruments include the dilruba, esraj, tanpura, ektara and the mayuri.  

Among the wind instruments the most popular is the Shahnai, a double-reeded flute. The bansuri has many variations producing different pitches and sounds. Other wind instruments include the bansuri, nadaswaram, ninkirns and pongi.  

There are many types of drums in India. The double-faced ones can be  hit on both sides, like the dholak or the pakhawaj. Similarly, the mridangam of the south used to accompany Carnatic music, is placed on the lap of a person and struck with the hands on both sides. The tabla on the other hand is a set of two single faced drums and is played using both hands. It is the traditional accompaniment for Hindustani music. Religious festivals in Kerala are incomplete without the large drums called 'chenda', which are beaten with sticks. The 'ghatam' is perhaps the most interesting as it is a big round clay pot. It is placed on the musician's lap and he taps it with his fingers and knuckles to produce the most exciting sounds.  

The last category 'ghana', has a wide variety of instruments that are percussion - based like bells, clappers, cymbals and gongs. They usually fulfill rhythmic functions that produce a variety of notes like the other instruments. The jal-tarang is a set of china bowls of varying sizes filled with different quantities of water, which produce different notes when tapped with a stick.