Indian classical music - Page 5

Ancient Scales and Modal Shift

In ancient times, different scales were created using a process we call modal shift (Grama Moorchana or GrahaBheda). If we start with the basic, 7 notes, we get a scale of natural notes (used in today's Bilawal / DhiraShankarabharanam). Then, if the reference pitch Sa (tonic) is shifted by one note, we get a completely different scale (Kafi/Karaharipriya). This happens because the relative pitch of various notes in the Just tempered scale are not the same (unlike in equal tempered, where a shift gives exactly the same scale). One more shift gives us yet another scale (Bhairavi/HanumaTodi). We can do this shifting a couple of more times to get a total of 6 different scales.

This method of generating different scales can be practically used, when a fixed fret instrument (Vina) is played. In ancient literature we continue to see references about this kind of Moorchana till the time of Sarangadeva. Practice of getting different scales by changing the pitch of notes (other than Sa and Pa) developed later.

Hindusthani Scale

First let us see how Hindustani scale can be derived. Starting with Sa of 240Hz for the sake of easy arithmetic, using the ratios as stated above, the nominal frequencies of Re, Ga, Ma, Pa, Dha and Ni come to 270Hz, 300Hz, 320Hz, 360Hz, 405Hz and 450Hz, in the Just or Pure (shudha) scale used in Hindustani Music. There is a geometric progression of scales with a note being 1.5 times the fifth earlier note. So,

Pa(360Hz)/Sa(240Hz) = Dha(405Hz)/Re(270Hz) = Ni(450Hz)/Ga(300Hz) = Sa'(480Hz)/Ma(320Hz) = 1.5

In the west, this is called the perfect fifths and attributed Pythagorous. There is considerable debate as to historically whether the Greeks got the scale from Indians or the other way round or they were independently developed. Additional notes are got by lowering the pitch of Re, Ga, Dha and Ni by one or two shruthis (microtones) to get Komal (flat) Reshab (R1), G1, D1 and N1. But Ma is slightly moved up to get Teevra Madhyam (M2). Thus we have 12 notes (Sa + 2 Ri + 2 Ga + 2 Ma + Pa + 2 Dha + 2 Ni) to an octave, just like in western music. The associated frequencies (nominal) are slightly different because an equal tempered scale is used in western music, instead of the pure scale, as can be seen in Table 2.

Sa and Pa are denoted as S and P respectively. For the other notes, small letters are used for the notes of lower pitch (r, g, d, m, n) and capital letters for the note of the higher pitch (R, G, M, D, N). Thus small letters denote komal notes, except Shudha Madhyam. Capital letters denote Shudh notes except Teevra Madhyam

In actual practice, all Indian notes except Sa and Pa, can move a microtone or two depending on the raaga . Sa, is thus called the reference note or tonic. Pa is the secondary reference.

Also, note that the absolute pitch of the basic reference note Sa is a variable in Hindustani music. It is set by the main artist according to his voice or the instrument. In western music, a standard has been established where the note A (Dha) has the frequency of 440Hz (which makes C, 261.63Hz). Usually, male vocalists in Hindustani use C(First White key) or C#(First Black key) as the reference note, Sa. The female vocalists use F#(Fourth black key) or G#(Fifth black key). Usually this reference is specified according to the harmonium keys, since harmonium is the accompaniment. Harmonium being a western import is tuned in equal temperament and thus is ill suited as an accompaniment, even though it is used because it is an economical alternative.

Shruthi

All Indian notes except Sa and Pa, can move a microtone or two depending on the raaga. This practice can be traced back to the ancient concept of Shruthi, where an octave is divided into 22 shruthis. Each of the 10 notes (i.e. excluding Sa and Pa) have two variants. For Eg. Komal Rishab (r) can be either the normal r or r+. The pitch difference between these two notes is small, but the use of one instead of the other, guarantees a simple ratio with the other notes used in that Raaga. That is the reason, why r is used in some Raagas and r+ is some others. It has been observed that the shruthis are such that, between two adjacent saptasvara notes there is a ratio of 256/243 and between shudh and komal notes the ratio is 25/24. It is this simple ratio that makes the music pleasing, natural and sweet. The 22 shruthis, their frequencies and equivalents are given in the table 3. An octave can be divided into 1200 cents. Scales are usually defined in cents so that for any base pitch, the scale can be calculated. The difference in cents between two frequencies, f1 and f2, is given as log(f1/f2) * 1200 * log(2) or approximately log(f1/f2) * 3986.3137.

Carnatic Scales

In Carnatic music, the scale is somewhat different, mainly in nomenclature. Carnatic also starts with 22 Shruthis for an octave. Even here the basic reference note Sa and the secondary reference Pa are fixed. Of the rest of 5 notes, 4 can be one of three Shruthis. In Hindustani, as given above, they can be only one of two. Ma though, can be only one two, in both Carnatic and Hindustani. But, not all the 3 pitches that can be Re or Ga are actually different. If we assign R1, R2 & R3 to the three possible Rishaba notes and G1, G2 & G3 to Gandhara notes, the actual pitch of R2 is same as that of G1 and R3 is same as that of G2. So, instead of 6 possible notes between Sa and Pa, we only have 4 (R1, R2 or G1, R3 or G2, G3). Similarly, we have four possible notes between Pa and Sa' of the next octave (D1, D2/N1, D3/N2, N3). So, even in Carnatic, we have 12 notes in the octave, even though they are referred to by 16 names.

This scale was first defined by Venkatamakhin and followed by most composers who came after him. This seemingly confusing nomenclature is only to accommodate some rare ancient Raagas within the structure of 72 Melakartha Raagas in Carnatic system as will be explained later.

Western Scales

The western music, now uses what is called the equal tempered scale, created around 19th century. Since there are 12 notes, and the octave is to be divided equally (in a logarithmic sense), each note is got by multiplying the previous note by twelfth root of 2 (which is about 1.059). Thus the actual frequencies used are slightly different from the pure scale used in Hindustani. The keys of a harmonium, piano or an electronic keyboard are tuned to this equal tempered scale. Some notes of equal tempered scale are very close to those of pure scale that only a trained musician can tell them apart. Some other notes are close, but not close enough, so that casual listeners can also make out the difference. The sensitivity of average listeners is about 5 cents and trained musicians as low as 2 cents. Some of the keys of equal tempered scale differ from just scale by as much as 16 cents, and some like the fifth (G or Pa) by a mere 2 cents. Equal tempered scale is a trade off between pure notes and ability to use any key to start a mode without retuning.

Raaga

Literally Raaga (or Raag in Hindi, also spelt Raga or Rag) means color, mood or feeling. Raaga is so called because, it creates a particular mood in the listeners. Raaga is a central concept in Indian music. A Raaga has many aspects to it. Only when all the aspects or characteristics of a Raaga are adhered to does the music sound like a Raaga.

Aarohana and Avarohana

Each Raaga has a particular scale. The ascending scale is called Aarohana and the descending scale is called Avarohana. A Raaga can have 7, 6 or five notes. A 7 note scale is called Sampooran (in Hindi) or Sampoorna (in Sanskrit) or heptatonic Raaga eg. Kafi or Shankarabharanam. Six note Raagas are called Shadava or hexatonic, 5 note Raagas are called Odava or pentatonic (eg. Durga, HamsaDhvani). Incidentally all over the world, pentatonic scales are common esp. in folk music. Unlike in the western modes, the Aarohana and Avarohana can contain different notes i.e. the ascending scale can be different from the descending scale (Eg Rageshri, Naata). Also, in some Raagas, the ascending or descending note sequence is not purely ascending or descending. In the middle there might be some reverse movement in a note or two (see Kedar, Sahana). Even though, two Raagas might use the same set of notes, this difference in the way ascending or descending note series is sung would make the two Raagas different.

Some Raaga scales do not even begin with the reference Sa (See Multani, Pannagavarali). Some Raagas may even skip the reference Sa. For eg. in Lalit, the ascent begins with the Mandra Sthayi Ni. The ascending Madhya Sthayi Sa (the tonic) is omitted and while descending the Tara Sthayi Sa' is omitted. Such Raagas do not traditionally occur in Carnatic, though. Raag Lalit also uses, both shudha Ma (m) and Teevra Ma (M). This is not allowed in Carnatic.

Vaadi, Samvaadi, Vivaadi

Each Raaga has one important note, called Vaadi (Sonant or King). The related note to this swara note is called Samvaadi (Consonant or Queen). Usually the Vaadi and Samvaadi notes are in simple ratio with each other making them rather pleasant as a pair, so ideally samvaadi is the fifth of the vaadi (ratio of 3:2), though a third or a fourth is the note used in most Raagas. Elaborate patterns are thus woven around these notes and also, they can be used as the stop notes in a musical phrase. The note which might be in conflict or dissonance with Vaadi is called Vivaadhi. The Vivaadi Swara in contrast is to be just touched upon or sometime entirely omitted in descent or ascent. The other notes in the scale which agree with vaadi are called Anuvaadi. Two Raagas with the same scale can have different Vaadi-SamVaadi-Vivaadi swaras making them different and giving them their characteristic flavour.

For eg. Deshkar and Bhoopali have the same Aarohana and Avarohana. Shudh Kalyan has the same Aarohana. But all three are different because of the stress placed on different notes. Deshkar and Bhoopali have their Vaadi and SamVaadi swaras switched. Also, in Deshkar Re is the Vivaadi, so it is fleetingly used. In Shudh Kalyan the descending scale uses two more notes Nishad and Teevra Madhyam, but fleetingly.

Ambit or provenance

Usually a Raaga needs to be elaborated in 3 octaves (Sthayi/Saptak). But, each Raaga has a characteristic octave which is more important than the others. Most of the time, the artist has to stay in this register (another name for octave). For eg. Darbari, Bhoopali are centered on mandra Saptaka, while Bihag, Shudh Kalyan primarily use Mandra-Madhya (i.e. the upper part of Mandra and lower part of Madhya). Gunakri, Deshkar use Madhya-Tara and Raag Desh, Adana use Tara Saptaka i.e. the upper register.

Pakad

Each Raaga has characteristic phrases or Pakad (meaning catch). The catch phrases help in identifying the Raaga and bring out its mood and also establish the important swaras vaadi-samvadi. For eg. the phrase for Deshkar is Ga-Pa-Dha-Pa-Dha,Dha-Sa, emphasizing the Vaadi and SamVaadi.