Purvi is Marwa with one more move: komal Re and tivra Ma stay exactly where Marwa puts them, and Dha falls to komal Dha. Three swaras have moved, in two directions, which is a shape only this frame and Todi have among the ten.
The seven swaras, from Sa
Declared as semitone offsets from Sa, then read through the same fixed chromatic-to-sargam table every thaat on this site uses — the frame’s seven available positions, not a raga’s actual phrasing. Against the Bilawal reference this frame moves three swaras.
| Degree | Offset (semitones from Sa) | Swara |
|---|---|---|
| 1 | 0 | Sa |
| 2 | 1 | Komal Re |
| 3 | 4 | Ga |
| 4 | 6 | Tivra Ma |
| 5 | 7 | Pa |
| 6 | 8 | Komal Dha |
| 7 | 11 | Ni |
Where it falls on the sitar
With Sa placed on C, every fret across all five strings whose pitch class is one of Purvi’s seven swaras — computed from the registry’s true open pitches and the instrument’s fifteen-fret board:
| String | Frets | Swaras |
|---|---|---|
| 5th string (C3) | 0, 1, 4, 6, 7, 8, 11, 12, 13 | Sa, Komal Re, Ga, Tivra Ma, Pa, Komal Dha, Ni, Sa, Komal Re |
| 4th string (G3) | 0, 1, 4, 5, 6, 9, 11, 12, 13 | Pa, Komal Dha, Ni, Sa, Komal Re, Ga, Tivra Ma, Pa, Komal Dha |
| 3rd string (C4) | 0, 1, 4, 6, 7, 8, 11, 12, 13 | Sa, Komal Re, Ga, Tivra Ma, Pa, Komal Dha, Ni, Sa, Komal Re |
| 2nd string (G4) | 0, 1, 4, 5, 6, 9, 11, 12, 13 | Pa, Komal Dha, Ni, Sa, Komal Re, Ga, Tivra Ma, Pa, Komal Dha |
| 1st string (C5) | 0, 1, 4, 6, 7, 8, 11, 12, 13 | Sa, Komal Re, Ga, Tivra Ma, Pa, Komal Dha, Ni, Sa, Komal Re |
The count again lands on forty-five, matching Bilawal and Marwa: two downward moves and one upward one balance out inside a fifteen-fret span. On the C strings, 1, 6, 8 and 13 light while 2, 5, 9 and 14 go dark. On the G strings the moved positions are 1, 6, 11 and 13 against 2, 7, 10 and 14 — a different set of frets expressing the identical three swara moves, because the string opens on Pa.
A frame, not a raga
Like Marwa, Purvi has no exact counterpart in this site’s 12-TET scale library, and the honest report is that the comparison finds nothing. Purvi, Puriya Dhanashri, Basant and Shree are conventionally classified here; Shree in particular is built around a treatment of komal Re and Pa that two ragas sharing this frame will handle in completely different ways. The seven positions are the beginning of the description, not the end of it.
Where to start
Play Marwa first and then lower Dha — that single change is the entire difference, and it is easier to hear as a change than to read as a table. From here, Todi is one further move, lowering Ga as well. Take all three to the fretboard explorer and follow the moved positions string by string rather than trying to memorise three separate frames.