Isai (Eng: Music) is a Tamil musical thriller film of 2015. S j Surya is everything in this film as he himself is doing almost all ingredients of the film. He is the director, producer, composor and more over hero of the film. Satyaraj and Savitri (debutant) performs the other important roles in this film. This is a musical thriller film and the story is thus related to music. A K siva (S J Surya) works as an assistant to the famous music director Vetriselvan (Sathyaraj) . Vetriselvan was a gifted musician of that time and there was no one to challenge him in the industry and is regarded as the greatest musician of the present time. Every one loves him and a work under him is considered as an award. Shiva also considered this opportunity as a blessing to him and was satisfied with the assistant job. Once he got an opportunity to compose music for a short film and from there the twist of the story begins. He got permission from Vetriselvan and he tried his best to compose it with some innovative ideas which he supressed till then and were afraid of its acceptability among the audience. Vetriselvan in his wildest dream didn't think of the danger that approaches him in the shape of Shiva. The introduction of new techniques and the use of synthesizers in his music gets attention of all music lovers and he was welcomed wholeheartedly by the industry. Gradually he became the most sought after musician and overtakes Vetriselvan. As became the No.1 director he builds his own studio. In the mean time he had a love and married that girl. As their life went on smoothly they got a new enemy, who was their old master. The jealously Vetriselvan couldn't bear this and tried his own way to clear out Shiva from the industry. In short a war broke out between the two musicians and for the unexpected climax, please watch the film. You have a surprise end waiting for you in this film. Music is liked by all and thus a story related with music. The film received positive reviews more and went on packed houses from the releasing dates itself. The performance of Veteran Satyaraj and the challenging role of S J surya were both competitive and complex. Both the actors did their role surprisingly good and the mental tension and pressure of jealousy were executed fabulously. The sudden growth of a musician from a short film to a great musian is somewhat unbelievable and the avoidence of the great musician from the industry so soon seems an exaggerated one. But it is a exceptional work of S J Surya with direction. The cinematography and music is also awesome. Along with musical thriller it is regarded as a psysiological thriller also. I wish to conclude this review with a quote from The Deccan Chronicle: "It is Suryah's intelligently woven brave attempt that enthralls the audience keeping them hooked to their seats. Cinematographer Soundarrajan should be lauded for capturing the right mood of the film with its alluring compositions. A bit of trimming would have helped. Nevertheless, with Isai Suryah sends out a strong message that he is back with a bang!".