stylistic:tone, quality:correction
A raga is a melodic framework for improvisation in Indian classical music akin to a melodic mode. Rāga is central to classical Indian music and a common feature of all types of world music. It is not unique to 'Indian Music'. Each rāga consists of an array of melodic structures with musical motifs; and, from the perspective of the Indian tradition, the resulting music has the ability to "colour the mind" as it engages the emotions of the audience. Each rāga provides the musician with a musical framework within which to improvise. Improvisation by the musician involves creating sequences of notes allowed by the rāga in keeping with rules specific to the rāga. Rāgas range from small rāgas like Bahar and Shahana that are not much more than songs to big rāgas like Malkauns, Darbari and Yaman, which have great scope for improvisation and for which performances can last over an hour. Rāgas may change over time, with an example being Marwa, the primary development of which has been going down into the lower octave, in contrast with the traditional middle octave. Each rāga traditionally has an emotional significance and symbolic associations such as with season, time and mood. The rāga is considered a means in the Indian musical tradition to evoking specific feelings in an audience. Hundreds of rāga are recognized in the classical tradition, of which about 30 are common, and each rāga has its "own unique melodic personality". There are two main classical music traditions, Hindustani and Carnatic, and the concept of rāga is shared by both. Rāga are also found in Sikh traditions such as in Guru Granth Sahib, the primary scripture of Sikhism. Similarly, it is a part of the qawwali tradition in Sufi Islamic communities of South Asia. Some popular Indian film songs and ghazals use rāgas in their composition. Every raga has a svara called shadja, or adhara sadja, whose pitch may be chosen arbitrarily by the performer. This is taken to mark the beginning and end of the saptak. The raga also contains an adhista, which is either the svara Ma or the svara Pa. The adhista divides the octave into two parts or anga – the purvanga, which contains lower notes, and the uttaranga, which contains higher notes. Every raga has a vadi and a samvadi. The vadi is the most prominent svara, which means that an improvising musician emphasizes or pays more attention to the vadi than to other notes. The samvadi is consonant with the vadi and is the second most prominent svara in the raga.