Drhupad - Hindustani Classical Music - Knol Notes
Dhrupad is the oldest existing form of North Indian classical music. The origin of this music is linked to the recitation of Sama Veda. Dhrupad is the oldest vocal and instrumental style. Dhrupad, a contemplative and meditative form, has been sustained by traditions of devotional music and worship.
The leading dhrupad maestros remark that dhrupad's purpose is aradhana (worship). The nature of dhrupad music is spiritual, seeking not to entertain but to induce deep feelings of peace and contemplation in the listener.
(Source: http://www.raga.com/text/221dhrupad_text.html )