Indian Classical Music And Sikh Kirtan by Gobind Singh Mansukhani (M.A., LL.B, Ph.D.) © 1982 Shruti (Microtone) |
| Shruti (Microtone) Shruti is the smallest unit of measurement of a note which is clear and audible. It is defined as “a note of minute pitch which the ear is capable of hearing”. It is called alaku in south India. Shruties are distinct microtones in an octave. These microtones represent unequal intervals presenting define expressive characteristics. “The 22 shruties cannot be produced in succession by the throat, but can be demonstrated on a stringed instrument. There are 22 shruties out of which seven main notes have been formulated as saptak. The number of shruties in each note are as follows: S: 4 shruties R:3, G:2, M:4, P:4, D:3, N:2. According to the laws of physics, a sound creates a number of vibrations and frequencies which can be measured, and the relation between two sounds (pitches) is the ratio between their vibrations. As such, S has 240 vibrations per second, R has 270, G-300, M-320, P-360, D-400 and N-450. It may be noted that svaras (notes) of the shajada grama (which begins with S corresponding to C scale) arise out of shruties and they may be represented as follows: Shruties: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | | | | | S R G M P 20 21 22 | | D N If the pitch value of a svara (note) is reduced by one or more shruties, it becomes Komal (flat); if it is increased it becomes teerva (sharp). The shruties in the madhyam grama (corresponding to F scale of western music) will be as under: Shruties: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | | | | | M P D N S 20 21 22 | | R G |