Module 3: Sound fundamentals · Lesson 1

Shruti and the tonic

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There is no fixed Sa

In Carnatic music the home note is called Sa. Unlike a piano key, Sa is not a fixed pitch. Each performer chooses the pitch that suits their voice or instrument, and that chosen pitch is their Sa for the whole performance. Every other note is then measured from it.

You can think of Sa as the zero on a ruler. You can slide the ruler anywhere, but the markings stay the same distance apart from one another.

Shruti: two meanings

The word Shruti is used in two ways, and it helps to know both:

1. In practice: shruti means the pitch you have chosen for Sa. A singer might say “my shruti is higher than yours”, meaning that their Sa is higher. The base Sa of a performance is called the Adhara Shadja .
2. In theory: shruti can also mean very small pitch steps. Old treatises describe 22 such steps in an octave. These are microtones that the old writers used to explain the notes, but today most teaching uses twelve note positions (see the swarasthana lesson).

How much the number 22 matters in today’s playing is debated. A school-board textbook says the count of 22 is commonly accepted but that opinions differ, and an encyclopedia notes research suggesting that the intermediate pitches heard in performance may be fewer or more than 22.

The drone that holds Sa in place

To make sure everyone hears the same Sa, a steady sound called the Drone plays throughout the performance. It is traditionally produced by the Tambura , a four-string instrument that sounds Sa and Pa, the note a fifth above it. Usually one string is tuned to Pa, two to Sa and one to the lower Sa; for a raga without Pa the first string is sometimes tuned to another note such as Ma. Today a Shruti box or app often replaces it.

The drone is not “accompaniment” in the sense of harmony. It is a reference that the ear compares every note to. This is why a note can sound very different in different ragas: its character comes from its distance to the drone.

Fixed and changing notes

Two of the seven notes, Sa and Pa, never change their pitch from raga to raga. They are called achala swaras , or fixed notes, and the drone sounds them. The others (Ri, Ga, Ma, Dha, Ni) can sit on different positions depending on the raga, which is why ragas have different characters. The next lessons explain how.