All the ragas are supposed to have been derived from their thaats. Every raga has a fixed number of komal(soft)
or teevra(sharp) notes, from which the thaat can be recognised. In other words, a certain arrangement of the 7 notes with
the change of shuddha, komal and teevra is called a thaat. There are several opinions in this matter. According to Pandit
V.N. Bhatkhande, the 10 thaats used to classify the ragas are --
1. Bilaval -- with all shuddh or natural notes.
2. Khamaj -- with the ni note as komal.
3. Kafi -- with the ga and ni notes as komal.
4. Asavari -- with the ga, dha and ni notes as komal.
5. Bhairavi -- with the re, ga, dha and ni notes as komal.
6. Bhairav -- with the re and dha notes as komal.
7. Poorvi -- with the re and dha notes as komal and the ma note as teevra.
8. Todi -- with the re, ga and dha notes as komal and the ma note as teevra.
9. Marwa -- with the re note as komal and the ma note as teevra.
10. Yaman -- with the ma note as teevra only.