Vidyasagar was born to a Telugu musical family, brought up in Bobbili, who got exposed to music at a very early age of 3 by his father Ramchander, who was a self-led musician. He underwent carnatic vocals training first and then started taking classical guitar classes in Chennai from Master Dhanraj along with A. R. Rahman and then later piano.
Vidyasagar became an independent film composer with the song En Anbe in the 1989 Tamil movie Poomanam. Vidyasagar started his music career with a Tamil film, he gained recognition in the Tamil music industry at a later stage. He shifted base to Telugu cinema in 1989.
In 1994–95, Vidyasagar was approached by Tamil actor-director Arjun, with whom he worked for many acclaimed musical films like Jai Hind, Karna and Subash. Their combination resulted in acclaimed Tamil language melodic songs like Malare and Padu Padu.
From 1996 to 2001 Vidyasagar mainly concentrated on Malayalam films. During this period, Vidyasagar also composed for a few Tamil movies like Nilaave Vaa and Uyirodu Uyiraga. He won four Kerala State Film Awards. About his stint in the Malayalam Cinema, Vidyasagar was quoted saying "I believe that it was a God sent opportunity for me to work in one of the finest film industries".
From the year 2002, he started composing churning out blockbusters in Tamil and Malayalam simultaneously, with Dhil, Run, Dhool, Ghilli etc. in Tamil and Meesha Madhavan, Kilichundan Mampazham, Pattalam, C.I.D. Moosa etc. in Malayalam.The song 'appadi podu' in Ghilli was accepted widely by all the listeners.Akshay Kumar brought the right of the song from Vidyasagar for the Hindi movie Boss. Every song of Meesha Madhavan was a colossal hit. The film too emerged as an all-time blockbuster.
During this period, Vidyasagar composed for his first English language feature, Beyond The Soul, a low-budget independent film directed by Rajiv Anchal.
Between 2003 and 2005, he composed songs for several notable films like Anbe Sivam, Madhurey, Ji and Chandrolsavam in 2004–05. The year 2005 saw Vidyasagar receiving his first National Film Awards for his music in the Telugu film Swarabhishekam directed by K. Vishwanath. The music in the film was predominantly Carnatic. The same year, he composed music for the film Chandramukhi, the only Rajinikanth starrer he has composed for till date. The songs become chartbuster, and so was the background score. Vidyasagar has notably used rare Carnatic ragas otherwise unheard of in film music in his compositions; Thendral ennum thereri (from the movie Pasa Kiligal) set to Nasikabhushani, or Ding dong koyilmani (from the movie Ji) set to Rasikapriya being some examples.
In 2007, Vidyasagar was signed by Prakash Raj for his production venture Mozhi starring Prithviraj Sukumaran and Jyothika. The film directed by Radha Mohan had critically acclaimed melodies like Kaatrin Mozhiye and Sevvanam. The songs of Mozhi had the distinction of being completely devoid of duets. The only female voice was of Sujatha Mohan in Katrin Mozhi. In 2008 Vidyasagar's notable releases were Vijay's Kuruvi and the Priyadarshan directed Mere Baap Pehle Aap in Hindi.
After his brief dull phase in Malayalam, he bounced back into the scene with the Lal Jose directorial Neelathamara, scripted by the legendary M.T. Vasudevan Nair, with the song Anuraga Vilochananaayi becoming a cult favourite. He followed it up with hits in Apoorva Ragam and Makeup Man. Meanwhile, in Tamil, he delivered hits with Karthi's Siruthai and Vijay's Kaavalan.
In 2012, Vidyasagar delivered two superhits in Malayalam with Diamond Necklace and Ordinary.
In 2013, Priyadarshan signed him in for his ambitious psychological thriller, Geethaanjali in Malayalam with Mohanlal in the lead role. Lal Jose's Pullipulikalum Aattinkuttiyum and Jannal Oram, the Tamil remake of Ordinary were his other releases of the year. The end of veteran filmmaker Sathyan Anthikkad's 10-film long collaboration with composer Ilaiyaraaja saw him join hands with Vidyasagar for the film Oru Indian Pranayakatha. The film became a success and Sathyan Anthikad continued his collaboration with Vidyasagar in for his next, Ennum Eppozhum which starred Mohanlal and Manju Warrier in the lead, which opened to packed theaters in 2015. The duos association is continuing, and Vidyasagar has created chart toppers for Anthikkad's latest movie Jomonte Suvisheshangal, released in 2017.