Reuniting with Roja director Mani Ratnam, A R Rahman flexes every one of his musical muscles for O Kadhal Kanmani. The soundtrack showcases Rahman’s versatility as it shifts effortlessly from hard-hitting hip-hop to soothing love songs. We even see a glimpse of the future, with Rahman’s son, A R Ameen recording a song—“Maula Wa Sallim”—for the album. Fans would be hard pressed to find a more accomplished soundtrack in 2015, capable of thriving without its accompanying film.