Prakash's introduction as a film composer was in the critically acclaimed Tamil film Veyil, directed by Vasantha Balan and produced by the director S. Shankar.
He first appeared as a vocalist on the soundtrack of director S. Shankar's Tamil film Gentleman, composed by his maternal uncle, A. R. Rahman. He has also contributed to some of Rahman's other projects. He had also worked with Harris Jayaraj and sang two songs in Anniyan and Unnale Unnale. His music in the film Madrasapattinam directed by A.L.Vijay was appreciated mainly for his song Pookal Pookum Tharunam.
He went on to win critical acclaim for his music in Selvaraghavan's drama film Mayakkam Enna, which became his third collaboration that featured Dhanush in the lead role. The album's five songs were written by Selvaraghavan and Dhanush, with the pair also coming together to sing the song, "Kadhal En Kadhal". The album also included the song "Pirai Thedum", which Prakash sang himself along with his fiancée, Saindhavi whilst another song, "Voda Voda Voda", written and sung by Dhanush, was composed in just 15 minutes and recorded within an hour. Rediff.com reviewed the soundtrack claiming that Prakash had "tried very hard to walk away from his comfort zone and provide the kind of edgy numbers Selvaraghavan demands, and has risen to the challenge". Critics from entertainment portal, Behindwoods.com, cited that Prakash "reiterates his talent once again" and gave a verdict that the album is "intoxicating enough". In late September 2011, a single track, "Oru Murai", written by Thamarai and composed and sung by Prakash in R. S. Infotainment's Muppozhudhum Un Karpanaigal was released.