In Hindustani classical music, vivadi (Sanskrit: विवादि meaning "dissonant") refers to pitches that are not part of the arohana or avrohana of a given raga. In general, vivadi are not to be played during an improvisation on a given raga. So, for instance, if a raga had the structure S R G m P D N S', S' N D P m G R S; in that case, r, g, M, d and n would all be vivadi. Although vivadi pitches are generally to be avoided during the playing of a given raga, they are occasionally added by skilled performers in order to introduce some color to an interpretation.
In Carnatic music
A swaram is said to be vivadi in relationship with another swaram. There are twelve notes or svarasthanas in Indian classical music. But there are 16 notes. Thus some notes occupy the same frequencies.
A ragam is vivadi if it contains vivadi swarams, especially with the vadi swaram of the ragam (vadi swaram means important swaram for that ragam or scale).
- Ragas in Carnatic music by Dr. S. Bhagyalekshmy, Pub. 1990, CBH Publications
- Raganidhi by P. Subba Rao, Pub. 1964, The Music Academy of Madras
Articles that discuss vivadi ragas and a review of concerts that mentions some of vivadi ragams
- A peep into Vivadi ragas
- A review of Chennai music concerts mentioning various Vivadi ragams - from The Hindu online (newspaper)