Raga Purvi, the "type-raga" of Purvi Thaat contains all seven notes. But the rishabh and the dhaivat are komal both in ascent and descent and the madhyam varies from teevra to shuddh whereas the gandhar and the nishaad stay shuddh throughout. In Puriya Dhanashree, however, the aarohan or the ascent is as follows - -N r G M d N S+. This shows that pancham is not used very often in the aarohan thereby making it a shaadav aarohan or an aarohan with six notes. Rishabh and Dhaivat are komal or flat in Raag Puriya Dhanashree wheres the Madhyam is teevra or sharp. The descent or the avarohan is as follows: S+ N d P M G M r G r S, the descent bears all seven notes with komal Dhaivat and Shadaj and a teevra Madhyam. The vadi of this raga is pancham and the samavadi is rishabh. Raag Purvi's structure is very close to that of raga Puriya Dhanashree therefore in order to differentiate between the two shuddha madhyam is often used in raga purvi unlike the teevra madhayam used in raga Puriya Dhanashree. The gayan samay or the time of singing this raga is at dusk. Raag Puriya Dhanashree is sung at time of transition from the afternoon to the evening and thus it is known as a Sandhiprakash Raga. The pakad of this Raga or the catch phrase of this Raga under the Bhatkande system is -N r G, M r G P, M d P, M G M r G d M G r S. While expounding the uttaranga part of this Raga the phrase M d N d S+ is used to move into the taara saptak. The transition from the taara saptak Re to the Madhya Saptak Ni is commonly through the use of a meendh.
Raga-Rasa Theory
Each sruti or micro tonal interval has a definite character; the names manda, candovati, dayavati, ranjani, raudri, krodha, ugra or khsobhini denote their emotional quality which dwells in combination or singly in the notes of the modal scale: thus, dayavati, ranjani and ratika dwell in the gandhara and each of the notes of the scale in its turn has its own kind of expression and distinct psychological or physical effect and can be related to a colour, a mood, a metre, a deity or one of the subtle centres of the body....Thus for the sringara and the hasya rasa, the madhyama and the pancham are used; for the vira , raudra and the adbhuta , the shadja and the rishabha ; for the bibhatsa and the bhayanaka , the dhaivata ; and for the karuna , the nisada and the gandhara are used. Every swara stands for a certain definite emotion or mood and has been classified according to its relative importance, and it forms a different part of the `person' of the modal scale.
