The Thaat System and How Ragas Are Classified
There are hundreds of ragas in active use across Hindustani classical music, each with its own melodic personality. Trying to memorize them one by one would be overwhelming — which is exactly why the thaat system exists. Thaats are ten parent scale patterns, formalized in the early 20th century by musicologist Vishnu Narayan Bhatkhande, that group ragas by which of the twelve swara positions they draw from in their basic ascending form.
Ten parent scales, hundreds of children
Each thaat is a specific seven-note (heptatonic) scale built from the
twelve available swara positions — some shuddha (natural), some komal
(flat), and, in one case, tivra Ma (written Ma# in prose, m in
Compose notation). The most familiar thaat to
Western-trained ears is Bilawal, which uses all shuddha swaras and
lines up with a Western major scale. Others, like Bhairav or
Todi, use striking combinations of komal and tivra swaras that give
ragas built on them a very different, more angular character.
A single thaat can be the "parent" of many distinct ragas. Ragas built on the same thaat share the same seven underlying pitch positions but differ in what actually makes a raga a raga: which notes are emphasized, which are avoided or used sparingly, the specific ascending line (aroha) and descending line (avaroha) — which are often not mirror images of each other — and which notes function as melodic anchors. We go deeper on those anchor notes in our piece on vadi and samvadi.
The ten thaats
Bhatkhande's system names exactly ten parent scales. Every raga in Hindustani classical music is conventionally assigned to one of these (with some genuine edge cases, covered below):
| Thaat | Character |
|---|---|
| Bilawal | All shuddha (natural) swaras — the "default," closest to a Western major scale |
| Kalyan | Shuddha, except tivra Ma — bright, expansive (home of Yaman and Bhupali) |
| Khamaj | Shuddha, with komal Ni — a little softer and more relaxed than Bilawal (home of Desh) |
| Bhairav | Komal Re and komal Dha — stark and grounded, the archetypal dawn sound (home of Bhairav) |
| Poorvi | Komal Re, komal Dha, and tivra Ma — a serious, twilight character |
| Marwa | Komal Re and tivra Ma, shuddha Dha — famously avoids resting on Sa, giving it a restless quality |
| Kafi | Komal Ga and komal Ni — a soft, folk-adjacent color (home of Bageshri) |
| Asavari | Komal Ga, komal Dha, and komal Ni — a somber, minor-adjacent feel (home of Darbari Kanada) |
| Bhairavi | Komal Re, Ga, Dha, and Ni — the most "flattened" thaat, used for a huge range of moods (home of Malkauns) |
| Todi | Komal Re, Ga, and Dha, plus tivra Ma — widely considered one of the most difficult characters to get right (home of Miyan ki Todi) |
Hear all ten
A table of komal/tivra markings only goes so far — here's each thaat's seven-note scale, playable in order, so you can hear the character the table above is describing rather than just reading about it.
Every raga currently on this site is grouped by one of these ten on the Ragas page, so you can hear several real examples of a given thaat's character back to back.
It's a classification system, not the whole picture
It's worth being clear about what thaat doesn't explain. Two ragas can share an identical thaat and sound almost nothing alike, because so much of a raga's identity lives in melodic movement and emphasis rather than just scale membership. Thaat is best understood as a cataloguing tool — useful for organizing and comparing ragas — rather than a complete description of what makes any individual raga distinctive. Some ragas also don't fit neatly into a single thaat at all, or use additional notes beyond their thaat's seven in specific ornamental contexts.
Why this matters for a sitar player
Recognizing a raga's thaat is often the first analytical step a student takes when learning a new raga, because it immediately narrows down which frets and swara positions will actually be used. From there, the real learning is in the aroha, avaroha, and phrasing — the parts that give the raga its identity beyond the raw scale.
Practice this: set a tonic on the Virtual Sitar and try playing through a few different seven-note combinations by ear — it's a quick, hands-on way to feel how different swara choices change the mood of a scale before you dig into named ragas. When you're ready for those, Ragas groups the site's core examples by thaat, with each one's aroha, avaroha, vadi, and samvadi laid out — and a Compose import so you can hear and play with the scale yourself. The glossary is a quick place to look up thaat, raga, sampurna, shadava, or audava if any of that vocabulary comes back up later without the full explanation attached.