In the world of ragas there are old ones and new ones. There are ragas identifiable by catch phrases and those created by speculating on scalar or modal combinations. While ragas such as khamboji, bilahari, bhairavi etc. would fall into the former group, ragas such as vaasanti, revati etc. would fall into the group of modern ragas with a scalar construct.

Udayaravichandrika is also a scalar raga; its distinction lies in the fact that itslakshana has been notated in older texts and has been followed by MuthuswamyDikshitar in the early 19th century.
Going by the various accounts of his lifestory, we are given to understand that Dikshitar composed the very rarely heardkriti 'Sri guruguhamurte' in this raga either in the very late 1790s or in the early 1800s.
Sri guruguhamurte is a powerful composition extoling the 'guru' enshrined in the 'guha' or the heart. It also illustrates how a scalar raga takes form in the hands of an extraordinary composer. The composition spans a wide tonal range from the lower pa to the ga above the octave and it has some fairly unique passages within the realm of what is assumed to be allowed within the five notes that make up the murchana.
It needs to go on record that Udayaravichandrika is a raga that is documented in the Venkatamakhi raga tradition and this is the only known composition in this raga.Thisudayaravichandrika is different from the one that is followed in Tyagaraja's tradition.
What does Udayaravichandrika sound like? Listen to an audio recording of Sri Guruguhamurte rendered by yours truly on You tube.http://www.youtube.com/watch?v=Lw2WW90YqbY
Simply put, the ‘scale’ of the raga is the same as that of suddhadhanyasiexcept with the other nishadha.(S G' M P N S - S N P M G' S).
For those of you who can hum the scale, try humming the phrase P M G' M G' S N and you will find the melody to be familiar. 'engeyokettamadiri'.
Yes, it is the song 'O vasantaraaja' from 1984.
What a composition!
The other day, I sang a line from the composition 'manmathakoyililpaalabhishekam' just to illustrate the total absurdity of lyrics to someone and the entire song came gushing along with memories from 1984.
Yes. O vasanta raja from 'neengalkettavai' is one song that instantly transports you back in time and for the most part (at least the pallavi) bears fidelity to the scale of udayaravichandrika, although the caranam (at manntottadaalindru and sevvanam pol aachu) and the bgm take the liberty of deviating from the murchana.
Yet another song that closely embraces the scale of udayaravichandrika (except for variations in the caranam and in the bgm) is jnaanjnaanpaadanam from the film Poontalir; sung by Jency, this song is representative of Illayaraaja in his fullest flow and form in the late 1970s.
Enjoy the feel of (the scale of) Udayaravichandrika!
About the author
Kanniks Kannikeswaran
www.kanniks.com