in relation to it. The ascent and descent of the notes in every raga are the two
other defining parameters of it, and is very important. Some ragas in the same
scale may differ in ascent and descent. The speed of a raga is divided into
three parts: Vilambit (slow), Madhya (medium) and Drut (fast).
    Another aspect of the ragas is their classification based upon the time of
the day or night for their performance. Thus ragas are of four types: (a)
Sandi-prakash ragas or twilight ragas, (b) Midday and Midnight ragas, (c)
Ragas for the first quarter of the morning and night, and (d) Ragas for the last
quarter of the day and night. However, at a broader level, all the ragas are
divided into two groups depending on their timing of performance. These are
Poor Ragas, sung between 12 noon and 12 midnight, and Uttar Ragas, sung
between 12 midnight and 12 noon.
    Yet another division of ragas classifies them into the six principal ragas:
Hindol, Deepak, Megh, Shree and Maulkauns. These six ragas give rise to
other derivatives. The first derivatives of the ragas are called raginis. Each
raga has five raginis under it. Every raga has a fixed number of komal (soft)
or teevra (sharp) notes which help recognize the thaat from which the raga
has been derived.
    Ragas of Carnatic music are categorised into the base or melakarta ragas
and the derived or janya ragas. Melakarta ragas have a formal structure,
whose basis is formed by the 16 swaras. While melakarta ragas follow a
fairly scientifically organised, the janya ragas stem from their usage and are
likely to evolve with the music. One of the facts that supports it is many
janya ragas change their character over time. As for janya ragas, they are
created from the melakarta ragas through various means. One of the she
simplest ways to generate a janya raga is to drop one or more of the swaras
in the ascent or arohanam and/or descent or avarohanam.
    There are 72 melakarta ragas that form the basis of Contemporary
Carnatic music. These "creator" ragas are also called janaka ragas and thai
(mother) ragas. Venkatamakhi (17th century AD) is stated to be the first to use
the 72 melakartas. His works are known to be the source of the current
system of contemporary Carnatic music. Earlier works generally contained
fewer melakartas and most of them had flaws in their organisation.
Muthuswamy Dikshithar"s compositions are generally based on the raga
names and lakshanams (definitions)         in this system, while Govindacharya