he rhythmic organization is based on rhythmic patterns called tala. The melodic foundations are called ragas. One possible classification of ragas is into "melodic modes" or "parent scales", known as thaats, under which most ragas can be classified based on the notes they use. Thaats may consist of up to seven scale degrees, or swara. Hindustani musicians name these pitches using a system called Sargam, the equivalent of the Western movable do solfege. Hindustani classical music is primarily vocal-centric, insofar as the musical forms were designed primarily for vocal performance, and many instruments were designed and evaluated as to how well they emulate the human voice.