Kaaviya Thalaivan (English: Epic Ruler) is the 2014 soundtrack album to the Tamil historical fiction film of the same name, written and directed by Vasanthabalan. A. R. Rahman has composed the original songs and score for the film. Being a period film, the music of film reflects the sounds during the 1920s pre-Independence Indian era. The album marks poet Vaali's last lyrical work for this A. R. Rahman musical film. Prior to recording the original songs, Rahman carried out a research for six months for the music. Majority of the tracks were recorded by nine months, beginning from October 2012. Every song in the film has an underlying concept that justifies the screenplay. The singles released prior to the album release were "Vaanga Makka Vaanga" and "Yaarumilla". The original version of the soundtrack album that released on August 18, 2014was aired through Suryan FM. The album met enthusiastic response from audience and positive critical acclaim. It topped the Indian Music Charts.

A. R. Rahman revealed that he backed out from the Hollywood fantasy film Seventh Son to compose for Kaaviya Thalaivan, because it gave him the scope to innovate with folk music like never before.He had done six months research for the music of the film, especially working on nuances of several ragas and folk music prior to recording actual compositions. From October 2012 to July 2013 Rahman finished composing 90% of the songs, prior to commencement of filming. The makers did not finish a schedule and waited for Rahman to give them another song.Initially, the makers were skeptical about A. R. Rahman's agreement to the project. For an undisclosed song in the album, Rahman composed the lyrical tuning to six different iterations.Rahman was well aware of singer Haricharan's strong foundation in classical music. Unlike usual recording routes, the composer and singer had an impromptu sort of jamming session. Haricharan was diffident on the over-dramatizing lyrical works but agreed later. As per The Hindu, he was quoted saying "It is a period movie about street theatre, I trained myself by listening to legendary singers such as S. G. Kittappa and M. K. Thyagaraja Bhagavathar." Haricharan has sung for ten tracks (inclusive of bit songs) in the album. The complete album was supposed to be written by Vaali but his untimely demise, he wrote the track "Alli Arjuna" for the soundtrack, his last poetic contribution to Tamil music. For this conversational track, Haricharan sang for both the characters 'Krishna' and 'Arjuna' by bringing alterations in his voice.As per the producer, S. Sashikanth, "Every song in this movie has a concept behind it. With "Yaarumilla" – that particular idea was based on the romance between Kitappa and KB Sundarambal. There were letters that Sundarambal had sent to Kitappa which are supposed to be on par with Shakespearan love letters! So the song’s inspiration comes from that."

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