Indian music of all types, in general and classical music, in particular, is based on raga (melody) and tala (rhythmic cycles). Musical notes of different series in their consecutive order of pitch within an octave form the basis of a raga. The Raga is a framework encompassing a set of rules prescribed for the melody, for the movements up and down the scale, for which notes are to be prominent, which notes or phrases are to be avoided, and so on. The framework also allows for endless variations within the set of notes. Thus, a raga is a particular arrangement of notes and melodic movements. However, it should be noted that as ragas were transmitted orally from teacher to student, some ragas vary across regions, traditions and styles.
In the Hindustani Classical Music sphere, ragas are many and each has its distinctive qualities. The essential feature of a raga is its power of evoking an emotion that enthralls listeners – that is, a Raga should 'colour' or please the minds of the listeners. There is also a broad time cycle that is followed while rendering a Raga. There has also been a growing tendency over the last century for North Indian musicians to adopt South Indian (Carnatic music) ragas, which do not come with any particular time associated with them. The result of these various influences is that there is increasing flexibility as to when ragas may be performed.
A raga is more than a scale. Many ragas share the same scale. The underlying scale may have five, six or seven swaras. Ragas that have five swaras are called audav ragas; those with six, shaadav; and with seven, sampoorna . Those ragas that do not follow the strict ascending or descending order of swaras are called vakra (nonlinear) ragas. Ragas are differentiated from each other by the prominence of certain fixed notes, and by the sequence of a particular note or distinctive phrases. According to Bhatkhande, each one of the several traditional ragas is based on, or is a variation of, ten basic musical scales or frameworks or thaats.
about the Thaat
Distinguishing between Similar Ragas