The Notes in an Octave
In Indian classical music, we divide an octave into 12 notes. We use a movable scale, which means that your octave can start anywhere you like. Your starting point is the tonic (called "sa" and denoted by "S" in Indian music), and all the other notes are defined in relation to sa. For notation purposes, each of the 12 notes in an octave has a unique identity, given by S, r, R, g, G, m, M, P, d, D, n, N.
Keyboard instruments are not appropriate for Indian music because they do not have pure intonation. However, they do make it very easy to explain and visualize music. So here goes. Pick any key on the keyboard as your sa. Then play 12 consecutive keys in ascending order including both blacks and whites to get all the 12 notes in an octave. Here are a couple of illustrations using the keys A♭ and C as sa. (The octave ends at N, but we always complete an octave by singing the first note of the next octave, and that is why the illustrations show thirteen notes).
Octave notated using A♭ as sa
Octave notated using C as sa
Table 1. The notes in an octave in Indian classical music
Let me explain some of the columns in Table 1 above. If you compare the Notation ID and Sol-fa Syllable columns, you will find that the notes r and R are both re; g and G are both ga; m and M are both ma; d and D are both dha; and n and N are both ni. Then moving to the Note Name column, you will find that these notes are modified by adjectives, shuddha (pure), komal (flat), or tivra (sharp). The notes re, ga, dha, and ni each have pure and flat versions, while the note ma has a pure and a sharp version. What this means is that these five notes can be sung in one of two ways - either pure, or flat/sharp in relation to the pure. The audio below demonstrates the difference between the pure and flat/sharp versions of each note. In each case, the pure version is sung first followed by the flat or sharp version.
The notes S and P, called sa and pa, have only one version each. This is because sa and pa form the backbone of the octave and always have a precise pitch relation to each other. If you sing sa at a certain pitch, then the pitch of pa gets fixed by this and that is the only pitch at which it can be sung. In total, therefore, there are seven distinct notes (called swara) in an octave - sa, re, ga, ma, pa, dha, and ni.
The "Notation ID" column gives you the names of the notes as they are used in musical notation. As noted above, with the exception of sa and pa, all the other notes (re, ga, ma, dha, and ni) have two notation IDs each. The lower frequency note is denoted by a small letter and the higher frequency note is denoted by a capital letter to distinguish between the two versions. The final sa in Table 1 belongs to the next octave and is notated S', with a quotation mark after it. Notes in octaves below or above your basic octave are notated with quotation marks before or after them to show which octave they belong to. Here are a couple of ways to notate the keyboard, one using C as sa and the other using A♭ as sa.
Entire keyboard notated using C as sa
Entire keyboard notated using A♭ as sa
The third column gives the Indian sol-fa syllables for the various notes. Sol-fa is called "sargam" in Hindustani classical music, an acronym created by combining the first four sol-fa syllables (sa re ga ma). Singing in sargam is not just for voice training in Indian classical music - it is also used as part of musical performance as one of the tools for improvisation.
In the video below, Pt. Venkatesh Kumar sings in sargam between 9:10 to 11:15 or so.
Pt. Venkatesh Kumar
The full names of the notes (shadja, rishabha, gāndhāra, madhyama, panchama, dhaivata, nishāda) are used only rarely.
The First Notes You Learn in Hindustani Classical Music
So, there are twelve notes in an octave just like there are colors in a spectrum. But for creating music, you usually choose specific notes from within those twelve notes to give yourself a theme. Since melody is so central to Indian music, we are always on the lookout for note combinations (scales) that offer significant melodic potential. These are called ragas, and we know of about 500 ragas in the Indian classical tradition now. Sometimes ragas fade out as they lose popularity and people stop performing or learning them, sometimes new ragas are born out of new encounters or mixing existing ragas to come up with surprising new melodies. A number of ragas have been derived from folk tunes sung in various parts of India. So long as a scale is versatile enough to be developed into a full-fledged raga, artists are happy to play with it and see where it takes them, and if the new raga stands the test of time, it may eventually receive a place of honor alongside the other classical ragas.
But one must begin somewhere, and all new students of Hindustani classical music begin by learning the scale comprising all the pure notes, S R G m P D N.
Table 2. Scale comprising all the pure notes
The Natural Origin of Notes
Musical notes correspond to certain frequencies (pitches) relative to the tonic (sa). These are frequencies at which the sound produced is clear and pleasing because it is consonant (i.e., in agreement) with the tonic. At other frequencies, the sound is dissonant (clashes with the tonic). The tonic is played constantly in the background in musical cultures that use a drone (similar to the tanpura in Indian music), but even when it is not physically played, it is present in our minds as we listen to music. The way our minds make sense of music is by being aware of the tonic and understanding the other notes in relation to it. Therefore, the pitches that are pleasing to hear are those that are consonant, and it is these pitches that are traditionally used for music by all cultures.
The video below has to do with vibrations, frequencies, and resonance. It will help you visualize what happens when you find a frequency that is consonant with the tonic, and why there are only some pitches that are pleasing while others are not.
The power of consonance