The Bilawal thaat consists of seven full notes (shuddh swara-s). The ragas belonging to the Bilawal thaat bear characteristic resemblance to the musical scale of the thaat, but have distinctly unique features of their own, in terms of the arrangement of notes as well as the time of the day they are associated with. Raga Bilawal is the prime raga of this thaat.

Pattern of swara-s in the thaat are Sa Re Ga Ma Pa Dha Ni
1. Raga Durga
Five notes are used as 'Ga' and 'Ni' are excluded
All notes are regular
Prime note is 'Ma'
Arohana (ascent)- Sa Re Ma Pa Dha Sa(h)
Avarohana (descent)- Sa(h) Dha, Pa Ma Re Sa
2. Raga Pahadi

Five notes are used as 'Ma' and 'Ni' are excluded
All notes are regular
Prime note is 'Sa'
Arohana (ascent)- Sa Re Ga Pa, Dha Sa(h)
Avarohana (descent)- Sa(h) Dha Pa, Ga Pa, Ga Re Sa
Thaat Kalyan

The kalyan thaat consists of seven notes where the 4th note 'Ma' (madhyam) is used as tivra(sharp). The ragas belonging to the Kalyan thaat bear characteristic resemblance to the musical scale of the thaat, but have distincitly unique features of their own, in terms of the arrangement of notes as well as the time of the day they are associated with. Raga Kalyan is the prime raga of this thaat.

Patten of swaras-s in the thaat- Sa Re Ga Ma(s) Pa Dha Ni
3. Raga Charukesi

All seven notes are used
'Dha' &'Ni' are flat
Prime note is 'Ma'
Arohana (ascent)- Sa Re Ga Ma Pa Dha(f) Ni(f) Sa(h)
Avarohana (descent)- Sa(h) Ni(f) Dha(f) Pa Ma Ga Re Sa 4. Raga Bhoopali

Five notes are used as 'Ma' and 'Ni' are excluded
All notes are regular
Prime note is 'Ga'
Arohana (ascent)- Sa Re Ga Pa Dha Sa
Avarohana (descent)- Sa Dha Pa Ga Re Sa

Glossary: I- Low scale, h-High scale, f-Flat note & s- Sharp note
The 10 thaat-s are: Bilawal, Kalyan, Khamaj, Bhairav, Puri, Marwa, Kafi, Asavari, Bhairavi and Todi.
Although entire ragas in themselves, the thaat-s provide a framework for the system as a whole. The notation of a thaat, which describes its musical framework, is quite defferent from the characteristic agrrangement and progression of notes during rendition through a raga. It is exposition that gives a raga its pakad (peculiarity) and chalan (character). Every, thaat consist of seven notes or swaras but with different characteristic (chalan).

Thaat is one of the most fundamental bases of classification in the Hindustani classical system. Developed by the learned musicological Vishnu Narayan Bhatkande, that offers a framework to classify several ragas based on their musical scales. The Hindustani classical music system has thus, 10 thaat-s. each that is a raga in itself and stands as a proud parent to several raga that belongs to its family.

This album features vocal renditions of the popular ragas belonging to Thaat Bilawal & Thaat Kalyan by the legends of classical music.