Music is an integral part of India’s culture. The outstanding feature of Indian music is the raga system. Every raga is a distinct musical entity by itself and possesses well-defined characteristics.
Musical compositions are concrete forms of the abstract raga. they are so many manifestations of the various facets of the raga. Whereas a musical composition presents only a certain aspect of a raga, the detailed alapana of the same raga enables us to see its full form. Theoretically, the number of ragas is infinite. Singing or performing raga alapana (raga exposition) demands the highest degree of musical training, culture and creativeness. Some ragas admit of an elaborate exposition. Such ragas are called major ragas. Ragas which admit of only a brief exposition are called minor ragas.
Raga is the pivotal concept of Indian music, introduced by Matanga Muni in 5th century.
‘||यो सौ ध्वनि विशेशस्तु स्वरवर्ण विभूशित:||
रन्जको जन छित्तानाम् सरागह कथितो बुधै:||’
– Sarangadeva’s Sangita Ratnakara
According to the above sloka, a raga is that which is beautified or decorated by the tonal excellence of swaras and varnas and which decoration gives pleasure to the mind of the listener.
‘|| रन्जयति इति राग:||’ is the etymological definition of raga i.e., that which pleases is raga. It colors the mind.
In order to have a melodic entity, a raga must take atleast five of the 12 notes of the scale and they are called as Audava (5 notes), Shadava (6 notes) or Sampurna (7 notes) raga.
The classification of ragas into Janaka ragas or Janya ragas is the most scientific system of raga classification. Janaka means generic and Janya means generated. There are 72 Janaka ragas based on 12 swarasthanas of the sthayi. The scheme of 72 melakarta ragas provides an excellent workable arrangement.
Bharata in his Natya Sastra (4th Cent. B.C.) says:
The Sangita Ratnakara of Sarngadeva in 13th century A.D. mentions the following Thrayodasa (13) Lakshanas:
“Graha, amsa, taara, mandra, nyaasa, apanyaasa, sanyaasa, vinyasa, bahutva, alpatva, antara maarga, shaadava and audava”
The last 3 lakshanas i.e., Antara marga, Shadava, Audava were ommitted, as they became separate types of Janya ragas.
Hence some musicologists suggest the first 10 as Raga Dasa Lakshanas.