What is a Thaat?

Ragas are based on ten basic thaats, or musical scales. Each thaat has a different combination of natural (shudhha) notes and flat (komal) or sharp (teevra) notes. This thaat-raga theory was developed by Vishnu Narayan Bhatkande, one of the most influential musicologists in Hindustani classical music in the twentieth century.

The ten thaats are: Bilawal, Kalyan, Khamaj, Bhairav, Poorvi, Marwa, Kafi, Asavari, Bhairavi, and Todi.

For example, ragas Yaman and Bhopali are based on Kalyan thaat, and raga Malkauns is based on Bhairavi thaat. Bhatkande's thaat-raga theory is not infallible, but it is an important tool for classifying ragas and for teaching music to students.

Most thaats are also ragas, but thaats are different from ragas. A thaat is a musical scale with seven notes presented in order of ascent. Unlike a raga, a thaat does not have separate ascending and descending lines or any emotional quality. A thaat has seven notes, but a raga does not need to use every note in a thaat.

Two ragas can have identical notes and yet be very different ragas. For example, Raga Shree and Raga Puriya Danashri have the same notes, but are unmistakably different in structure and temperament. The first can be identified by its continual exploration of the relationship of the note Re to the note Pa; while the repetition of the phrase Ma Re Ga Re Ma Ga is an enduring feature of the latter. Knowledge of the thaat on which a raga is based or of the notes of a raga is a convenient starting point, but does not ensure a true familiarity with the raga.

Classification of Ragas by Thaat

Name of Thaat	Notes	Ragas
Bilawal	S R G M P D N	Kaushik Dhwani, Durga, Hemkalyan, Nat Bihag, Bihagada, Hamsadhwani, Deshkar, Shankara, Alahiya-Bilawal, Bihag
Kalyan	S R G M (sharp) P D N	Shuddha Kalyan, Yaman, Hameer, Hindol, Bhopali, Kamod, Chhayanat, Shyam Kalyan, Nand, Kedar, Gaud Sarang, Yaman Kalyan, Chandini Kedar
Khamaj	S R G M P D N	Khamaj, Desh Gaud Malhar, Gawati, Gorakh Kalyan, Jayjaiwanti, Jhinjhoti, Jog, Rageshri, Sorat, Tilak Kamod, Tilang
Bhairav	S R G M P D N	Bhairav, Ahir-Bhairav, Gauri, Gunkali, Jogia, Kalingada, Nat Bhairav, Ramkali, Vibhas
Poorvi	S R G M (sharp) P D N	Poorvi, Basant, Lalit, Paraj, Shree, Puriya Danashri
Marwa	S R G M (sharp) P D N	Marwa, Bhankar, Batiyar, Lalit, Puriya, Puriya Kalyan, Sohini, Vibhas
Kafi	S R G M P D N	Kafi, Abhogi, Bageshri, Bahar, Barwa, Bhimpalasi, Brindavani Sarang, Chandrakauns, Dhaani, Gara, Jog, Megh, Mian Malhar, Nayaki Kanhada, Patdeep, Piloo, Ramdasi Malhar, Shahana, Shuddha Sarang, Surdasi Malhar
Asavari	S R G M P D N	Adana, Asavari, Darbari Kanhada, Desi, Dev Gandhar, Jaunpuri, Kaunsi Kanhada
Bhairavi	S R G M P D N	Bhairavi, Bhupal Todi, Bilaskhani Todi, Komal Rishabh Asavari, Malkauns
Todi	S R G M (sharp) P D N	Todi, Gurjari Todi, Lilavati, Multani

Bibliography

Batish , Ashwin, and S. D. Batish. "The 10 Thaats of North India." RagaNet. 1997. Batish Institute of Indian Music and Fine Arts. 17 Apr. 2009 <http://raganet.com/RagaNet/Issues/2/10thaats.html> .

Chaudhuri, Amit. "Thaat." Know Your Raga. 2001. ITC Sangeet Research Academy. 4 May 2009 <http://www.itcsra.org/sra_raga/sra_raga_that/sra_raga_that_index.html>.