Jayachandran began learning Carnatic music at the age of 5 under Attingal Harihara Iyer and later under Perumbavoor G. Raveendranath. Thereafter, he was a student of Neyyattinkara Mohanachandran for 18 years. He won the Carnatik vocal competition at the Kerala University youth festival four times in a row from 1987 to 1990. He began his career in the film industry as a playback singer for the movie Vasudha in 1992, then became an assistant to Malayalam music director G. Devarajan. In 1995, he became an independent music director through the film Chantha.
Jayachandran was born to Madhusudhanan Nair and Sukumari Amma on 5 April 1971. He completed electrical engineering graduation from College of Engineering, Trivandrum He had worked at Asianet before taking up full-time music direction. He married Priya on 12 November 1995. He has been on the judging panel of musical reality shows in Malayalam television.