Saptak
Saptak means "gamut" or "the series of seven notes". It denotes the set of swaras i.e. Shadja, Rishabha, Gāndhāra, Madhyama, Panchama, Dhaivat, Nishada, Shadja which comprise a musical scale in Indian classical music. In Sanskrit, saptak literally means "containing seven" and is derived from the Sanskrit word Sapta which means "seven". The Saptak comprises the Sapta Svaras, i.e. the seven svaras or the seven notes of classical music.
The basic saptak is called the Madhya Saptak. For notes with lower frequencies, the artist may use the Mandra Saptak ', which is an octave lower than the Madhya Saptak. For notes with higher frequencies, the Taar Saptak, which is an octave above the Madhya Saptak, is used.
The usual scale of Indian music spans from Sa in the Madhya Saptak to Sa in the higher, Taar Saptak. This inclusion of the first note of the higher saptak makes eight notes instead of the seven in each Saptak.
Generally, a raga involves notes from three saptaks. The notes in the lower saptak are denoted by an apostrophe before the note representation and the notes in the upper saptak are denoted by an apostrophe after the note representation.
For example:
- Mandra Saptak : Ṣ or Ş or 'S
- Madhya Saptak : S
- Taar Saptak : Ṡ or Ŝ or S'
Considering the Sa of the Madhya Saptak, the frequencies of the other svaras would be,
Sa Re Ga Ma Pa Dha Ni
'''Mandra Saptak: 120 Hz, 135 Hz, 144 Hz, 160 Hz, 180 Hz, 202.5 Hz, 216 Hz.