The word ‘raga’ comes from the Sanskrit word ‘Ranj’, which literally means to delight or to make happy and satisfy a person. The ragas form the basis of the melody, while the tala becomes the basis of the rhythm. Each melodic structure of the raga has something similar to the distinct personality subject and the mood evoked by the sounds.
The basic element necessary for the working of a raga is the note on which they are based. According to the number of notes in the raga, there are three main jaatis or categories:
Audav/Odava Raga: is the ‘pentatonic’ raga, contains 5 notes
Shadava Raga: is the ‘hexatonic’ raga, contains 6 notes
Sampurna Raga: is a ‘heptatonic’ raga, contains 7 notes
A raga is neither a scale nor a mode but it is a scientific, precise, subtle and aesthetic melodic form with its own peculiar ascending and descending movement, which consists of either a full octave, or a series of 5 or 6 or 7 notes. There are three major types of Raga or Raga Bhed.