“Thrayodasa Lakshanas”–the thirteen characteristics of a Raga–which establish the swaroopa or melodic entity of the raga.
Since the raga system from the foundation of Indian Music, every writer from Bharatha has paid attention to the clear explanation of the subject. Many writers mention 10 lakshnas under which the individuality of a raga can be studied. Bharatha in his Natyasastra says:
Graha, Amsa, Tara, Madra, Nyasa, Apanyasa, Alpatva, Bahutva, Shadava and Audava are the 10 lakshnas of jatis. Jati was the term used in early times to denote a raga. In the Ramayana, the word jati is used instead of raga. The term raga came of use in the musical sense in the post – Bharatha period. The Sangitha Ratnakara of Sarangadeva mentions the following trayodasa lakshnas: Graha, Amsa, Tara, Madra, Nyasa, Apanyasa, Sanyasa, Vinyasa, Alpatva, Bahutva, Antaramarga, Shadava and Audava. The Sangita Sudha of Raghunatha Naik also mentions these trayodasa lakshnas. Venkita Makhi in his Chaturdandi Prakashika says only about Graha, Amsa, Tara, Madra, Nyasa, Apanyasa, Sanyasa, Vinyasa, Alpatva and Bahutva. Antaramarga, Shadava and Audava were omitted because they become separate types of janya ragas. A few of these lakshanas have have either become obsolete or are of mere acadamc interest to us in the present day.
The thirteen characteristics of a Raga are: According to the type of swara:
1. Graha Swaram
The note on which the Raga is commenced. Starting note of a Sangathi or Item or Ragam. There may be One, Two or even more Graha Swaras in a Ragam.
2. Amsa/Jiva Swaram
The note which revealed the melodic entity or the Swaroopa of the Raga (Soul of the raga). To show the Swaroopa of the Raga in an Alapana or sangathi, this note is sung repeatedly, very often. This can be considered as the main swara of the raga. There can be one or more amsa swaras in a raga.
Graha, Amsa, Nyasa Swaras are mandatory for the raga. If not specified Shadjam assumes the role of these three.
3. Nyasa Swaram
Ending note of the raga; the note on which the Raga was concluded.
According to the octave:
4. Mandram and 5.Tharam The lowest and highest notes respectively, beyond which the raga sancharas should not extend. Mandram defines the notes that are singable in the Mandra Stayi for the particular Raga. The swaras lower than that should not be sung/performed. Similarly, Thara Swaram defines the notes in Thara Stayi which are allowed in the raga.
According to the timing or usage of swaras:
6. Apanyasam
A Raga Alapana is done in different sections or parts or stages. Apanyasam is the starting note of each section.
7. Sanyasam
The ending note of each section in the raga alapana.
8. Vinyasam
In each section of the Raga alapana, Vinyasa is the note used to show the raga kala/chhaya or the essence of raga.
9. Bahuthwam
The note that is used frequenty in the raga. It has two sub-types: Alanganam and Abhyasam. Sancharas revolve around these notes.
10. Alpathvam
The note that is used sparingly in the raga. Two sub-types are: Langanam and Anabhyasam.
Langanam: The swara is pronounced, but the note sung is actually the neighbouring tone. So, though the Langana Swara appears to be performed, the actual shruti/frequency of that swara is rarely performed. It’s like creating an illusion of that swara being sung, while the actual swara sounded is different. Anabhyasam: A note that’s completely omitted or rarely performed.
11. Antaramarga
The introduction of a note or Chhaya belonging to the raga.
12. Shadavam
A Raga constituted of 6 notes.
13. Audavam
A Raga constituted of 5 notes.
Other Lakshanas:
Vadi, Samvadi: Vadi denotes the most important note of the Raga, and Samvadi as the second most important note of the Raga. However, Vadi means a speaking note, or any note of the Raga. Samvadi is a consonant note of the Vadi note which is generally its fourth (Madhyam bhav) or its fifth (Pancham bhav).
Anuvadi: Anuvadi is a note descibed as being in harmony, typically the third (Tivra Gandhar or Komal Gandhar) of a note.
Vivadi: Vivadi literally means a contesting or argumentative. Musically, it means a note so close to the original that one can see the tension between the notes. To illustrate Vivadi notes, we take an example of a scale which is used for Sama Gana (recitation of Sama Veda), and can be considered equivalent to today's Raga Kharaharapriya.
Hrasva: A Hrasva note is one on which a musical phrase does not linger for a length of time.
Deergha: A Deergha note is one where a musical phrase can halt for a considerable time.
Hrasva and Deergha are also applicable in lyrical compositions where they mean short vowels and long vowels. This is best illustrated in a Pallavi.
Aarohi: An Aarohi phrase is an ascending set of notes. For example, Sa Re Ga ma Pa.
Avarohi: An Avarohi phrase is a descending set of notes. For example, Dha Pa ma Ga Re.
Sthayi: Sthayi literally means constant. Musically, it refers to a fixed note around which musical phrases revolve. A Sthayi is used in the context of a musical phrase or to define an octave. A few examples of Sthayi phrases (taking Sa as the Sthayi note) in Raga Shankarabharnam are: Sa Re Ga ma Pa Dha Ni SA, Sa Re Sa and Sa Re SA
Conclusion:
To summarize, a Raga is a concept originating from Jati and can be defined as a musical scale, together with a set of Lakshanas and Lakshya which results in a consistent, recognisable musical framework. Within the reference of a Raga, an artist can attempt to improvise and develop the Raga through a musical performance.
Now for a given Raga, each of these Lakshanas mentioned above are clearly defined. Through a cycle of listening, learning, practicing and performing, a student can learn the Lakshana aspect of a given Raga as well. However, these only define the framework and by themselves do not make music. An artist has to apply Lakshya to their rendition and create a Raga presentation which can be described as Ranjayati (that which illuminates, gratifies and colours the mind). This is the most important characteristic in the presentation of a Raga.