Listen to Unnai Ondru Happy online. Unnai Ondru Happy is a Tamil language song and is sung by Viswanathan-Ramamurthy and P. Susheela. Unnai Ondru Happy, from the album Legends Kannadhasan - Vol - 3, was released in the year 1999. The duration of the song is 3:29. Download Tamil songs online from JioSaavn.