As we know, folk music is the mother of all music. The foundations of all genres of music were laid on the music created by ancient men in their different environs. The music that we call “classical music” was carved out of “folk” tunes and by setting standards of grammar and refining it.
In the Vedic times people used to chant religious mantras on three surs (notes) only. These notes were probably Kharaj (Sa), Madham (Ma) and Pancham (Pa). It is obvious that an enjoyable melody cannot be created on three notes alone. With the advent of the Aryans in the subcontinent, folk compositions were amalgamated into the original 3-note chants, and a new kind of music evolved that was called marg. With the passage of time people who excelled in this music were called gandhro. Gandhro music was so called because it flourished in the area that was called Gandhara (Kandhar, Peshawar, Attock, Taxila, Rawalpindi etc.)
The 50-years reign of Akbar the Great can be called the golden era of Chrupad singing. Earlier, this genre of music was confined to the religious environment of the temple. Tansen brought it to the Mughal court.
As against Kheyal gaiki, which is attributed to Sultan Husain Sharqi, and later to Naimat Khan Sadarang (Mohammad Shah Rangeelay period), Dhrupad gives more stress on alap
(free improvisation of raag without measured rhuthm, and designed to unfold melodic themes). Dhrupad is also practiced without the embellishments of tans and sargams, which are and essential part of kheyal. The accompanying rhyuthm too is played on pakhawaj instead of tables.