What is a Raga? One may ask. 

Raga system has been around for centuries, preserved in pristine purity in some parts of India, like in the south while absorbing new ideas and evolving into similar yet unique tonal signatures as in north Indian system. 

Simply speaking a Raga is an unique set of notes, derived from the Indian octave system which comprises of not seven but twelve notes. Originally, it was perceived that there were six Raga and thirty six "Raagini". The melodic combination of a Raga carried the so called "male" essence of music, namely strength, span and intensity of melody. In contrast, a Raagini was softer, more melodic and more fluidic in nature. With time, the concept of Raagini got lost and melodic combinations were being referred to as just "Raag" in North Indian system and "Ragam" in south Indian system. 

One may poetically express that a Raga is like a blank sheet of paper, with a set of pen that writes with a certain color ink. It's a frame, a tool, with which one may write poetry but the paper is not the poetry although without the paper and the pen, poetry can't be written. 

Each Raga has an unique set of Ascending notes, referred to as an "Aroha" and a descending set of notes, referred to as an "Abroha". The sequence of  Aroha and Abroha may be combination of the same notes, in forward or reverse order or they may be different. For example:

 Raag Bhoopali;     Aroha -  SA     RE      GA  PA   DHA  SA

                                   Abroha- SA   DHA   PA   GA   RE   SA

 

Raag  Yaman;         Aroha