In Hindustani classical music, thaats provide the framework for raga classification. A thaat is a sequence of seven notes (swaras) arranged in ascending order, containing both natural (shuddh) and altered (vikrit) notes. This system was formalized by musicologist Vishnu Narayan Bhatkhande, who introduced the concept of 10 principal thaats to make the vast world of ragas easier to study and understand.
The 10 thaats are Bilawal, Kafi, Khamaj, Asavari, Bhairavi, Bhairav, Todi, Poorvi, Yaman, and Marwa. Each one creates a unique melodic framework and serves as the foundation for several ragas. For instance, Yaman thaat (with tivra Ma) produces ragas like Yaman and Kalyan, while Bhairavi thaat (with several komal notes) gives rise to expressive ragas like Bhairavi and Malkauns. By studying thaats, students not only understand the structure of ragas but also learn how different note combinations shape the mood, emotion, and time of performance in classical music.
