K.R.S. Murthy

The following are experiments in shruthi as well as swara manipulation in a raga. The effect of shruthi manipulation manifests as a change in the perceived raga. I call it raga illusion.


Difference of one or more swaras in a raga. The raga changes by this action. Three types of swara vyathyasa are possible. They are:

Swara Lopa or Swara Omission

One of the swaras is omitted from the raga. If the raga is a Sampoorna Raga (a raga with 7 swaras), omission of a swara results in a Shadava Raga (a raga with 5 swaras). Similarly, a Shadava Raga becomes an Audava Raga (a raga with five swaras) when a swara is omitted. In Indian Classical Music tradition a raga should have at least five swaras. Similar swara omission technique can be used for ragas which have different number of swaras in their Aarohana (ascending order) and Avarohana (descending order).

Before Omission

After Omission

Sampoorna Raga

Shadava Raga

Shadava Raga

Audava Raga


Audava-Shadava Raga


Swara Agama or Swara Addition

A swara is added to a raga.

Before Addition

After Addition

Shadava Raga

Sampoorna Raga

Audava Raga

Shadava Raga

Audava-Shadava Raga

Shadava-Sampoorna Raga


Swara Adesha or Swara Substitution

A different swara is substituted for a swara in a raga. The raga changes, but the total number of swaras remains the same.


Shifting of the shruthi with the ascending order and descending order unaltered. In this experiment, the player hears the shruthi through an ear phone and plays the raga with that shruthi (shruthi-P) as the reference (adhara shruthi) for the raga. The listener hears the music played, but the listener hears the shruthi (shruthi-L) through an ear phone. The player and the listener can be fed two different shruthis by isolating the ear phone channel feeds.

First, a shruthi is fixed and a raga (raga-1) is played following the definition of the raga. The player and the listener hear the same shruthi (shruthi-P = shruthi-L). The player of the raga continues to receive the same shruthi (shruthi-P). The original shruthi is isolated from the listener and a new (shifted) shruthi (shruthi-L is not equal to shruthi-P) is delivered to the listener. The player continues to receive the original shruthi. With the new shruthi, which is different from the shruthi heard and used as a reference by the player, the listener hears a new raga (raga-2). So, the listener enjoys the illusion of the raga-2 isolated from the raga-1 played by the player. Thus, isolation can be achieved between the player and the listener.

Multiple listeners can be used in the experiment. By this technique, different players can enjoy the illusion of different ragas.

Following experiments can be conducted for raga illusion by a variety of shruthi pallata techniques.

Shruthi pallata by one step only. For example, from Sa to Ri1 (up-step) or Sa to Ni2 (down-step). Here the Ni2 belongs to lower octave.

Shruthi pallata by multiple steps. For example, from Sa to Ri2 (up-step) or Sa to Ni1 (down-step). Here the Ni1 belongs to lower octave. Similarly Sa to Ga (1 or 2) or Sa to Dha (1 or 2) (lower octave).

The shruthi slides from one shruthi to the other. By controlling the slide, the illusion can be manipulated. As an option the sliding can be continuous and need not stabilize.

The shruthi slides from one to the other till it reaches the destined shruthi and stays at the new shruthi. This technique, when properly implemented, can produce the illusion of raga malika (chain of ragas).


Two or more shruthis can be used at the same time. In this technique, the listener hears two or more shruthis at the same time. The player, however, can receive (or concentrate on) only one shruthi (shruthi-P). More than two shruhis requires a careful shruthi administration technique.

In this technique, one of the shruthis is dominant with the other shruthi as subordinate. Major and minor shruthis can be distinguished by loudness, tonal quality, precedence and other techniques to be explained later. The two shruthis can switch their roles between major and minor by sliding or step movement. For example, the major shruthi which has more loudness (volume) can decrease in loudness, while the minor shruthi originally less loud gains volume. This switch in roles between the major and the minor shruthis has to be administered very carefully, especially during the crossover. Also, the rate of change of the loudness (slope of change) has to be experimented to get pleasant effects.

One major and multiple minor shruthis are administered. All the minor shruthis (or selected numbers at a time) are present all the time.

Only major shruthi is present all the time, but only one minor shruthi is present at a time. The minor shruthis can be administered in sequence (increasing frequency order), in definite order (with a rhythm or tala) or in random.

The major and minor shruthis can be distinguished and distinctly administered by the following techniques:

Distinction in loudness: In practice, loudness can be controlled by absolute loudness as well as effective loudness. By a proper selection of the shruthi source the effective loudness can be controlled. Location is not only distance from the listeners ears, but also relative distance with respect to the two ears of the listeners. It should be kept in mind that the human ears are stereophonic receivers in nature. I plan to discuss the exploitation of the stereophonic nature of our ear in one of my future topics. Distinction by time duration of the shruthi presence. By using precedence or historical duration of the presence of the shruthi, major and minor distinctions can be achieved. Distinction can also be achieved by the tonal quality of the musical instrument producing the shruthi.


Percussion instruments are used as shruthi. The percussion instrument can be as simple as a Cymbal or an instrument like Tabla or Mridanga. Two Tablas or Mridangas can also be used for dual Shruthi techniques explained before. The two drums of the Tabla or the two sides of the Mridanga can also be tuned for two shruthis in the dual shruthi technique.

Musical instruments like Sitar Veena or Guitar can also be used for single or multiple shruthis.

Musical Illusion CDs and Tapes (Even Karaoke Illusion)

Music CDs and tapes could be produced with stereophonic outputs, in which one input to the earphone could be used to administer the shruthi. Options could be given to the listener to select any given adhara shruthi out of some selections, or the listener could input a shruthi of choice externally. The slogan for such CDs and tapes could be

"Create your own musical illusion".

Similar ideas could be used for Tala also.


The following are experiments in tala or rhythm.


In this technique two talas are used. Two talas can be played or administered by the following methods:

Dual Stable Talas

Two simple tala instruments like Cymbal are used to provide basic tala beats. The two tala instruments will have two distinct tala beats. To distinctly administer the talas two separate tala instruments are used. Even same type of instruments (Cymbal) but of distinct shruthi (pitch) can also be used.