Dhrupad Gayaki- Hindustani Music

Dhrupad is the oldest musical form of Indian Classical Music. Dhrupad gayaki comprises of 2 parts namely 'Aalap' and 'Composition or Bandhish'. It is restricted to a relatively smaller audience and is always accompanied by an instrument called 'Pakhawaj'. Dhrupad is performed in 4 styles namely 'Gaurahari', 'Nauhari', 'Dagari' and 'Khandari'. But only 'Dagari' style exists today. Dhrupad are based on themes like Religion, Philosophy, Praise of deities, Celebration of seasons. Dhrupad is the most strict form in terms of grammar and presentation and its musical parts are strongly systematized. It has certain fixed rules for execution. It starts with the aalap (which follows the three stages of Vilambit, Madhya and Dhrut laya) followed by a fixed composition which is divided into 4 parts-

1. Sthayi- Base or first section
2. Antara- Intermediate section 
3. Sanchari- Free flow
4. Abhoga- Last section or component

The literary meaning of Dhrupad is derived from the words 'Dhruva' and 'PADA'. 'Dhruva' is the steadily directed star that moves through our galaxy and 'PADA' means poetry. However, conceptually, it has a different meaning- It refers to the circulatory construction of our music. 'Dhruva' means a pole, a stand point. It implies the return of the 'Swara' (tonal), 'Kala' (time) and 'Shabda'(textual)  trajectories to a fixed point. All music forms existent today has attained this height of construction because of Dhrupad. That's why, it is called the soul of Indian Classical Music.

Prahars in Indian Classical Music

In Indian Classical Music, whole day(24 hours) is divided into 8 Prahars - 4 prahars of the day and 4 Prahars of the night.

The four Prahars of the day corresponds to-
Pehla Prahar 6:00 A.M. to 9 A.M is called Purvaanha
Doosra Prahar 9:00 A.M. to Noon is called Madhyaanha
Teesra Prahar Noon to 3:00 P.M. is called Aparaanha
Choutha Prahar 3:00 P.M. to 6:00 P.M. is called Saayankala

The four Prahars of the night corresponds to-
Pehla Prahar 6:00 P.M. to 9 P.M is called Pradosha
Doosra Prahar 9:00 P.M. to Midnight is called Nishitha
Teesra Prahar Midnight to 3:00 A.M. is called Triyaamaa
Choutha Prahar 3:00 A.M. to 6:00 A.M. is called Ushaa

Thaat System in North Indian Classical Music

Pandit Vishnu Narayan Bhatkhande (1860-1936) who was one of the most influential musicologist of North Indian Classical Music has created the Thaat System. He introduced 10 basic thaas in North Indian Classical Music. As per him, each raga is based on or a variation of one of these 10 thaats. These thaats are as follow:

1. Bilawal
2. Khamaj
3. Kalyan
4. Bhairav
5. Purvi/ Poorvi
6. Marva
7. Bhairavi
8. Asavari
9. Kafi
10. Todi

Each raag is based on one of these several thaats. As per Pandit Bhatkhande only those scales that follow the below mentioned rules will be considered as Thaat-

• A Thaat must have 7 swars out of 12 swars (7 Shudh, 4 Komal and 1 Tivra)
•  The swars must be in ascending order (Sa re ga ma pa dha ni)
• Whether Shudh or altered, both versions of a single swar are not allowed.
• Unlike Raga, a Thaat does not have separate ascending or descending orders. 
• A Thaat does not have any emotional quality which the ragas have.
• Thaats are not sung but the ragas derived from the thaats are sung.

Bhatkahande ji named his Thaats after the most important ragas that were associated with that Thaat. For e.g. Asavari was named after its prominent raag Asavari. Similarly Kafi after raag Kafi, Bhairav after raag Bhairav etc.