Listen to Undun (In the Style of Guess Who) [official Instrumental Backing Track] online. Undun (In the Style of Guess Who) [official Instrumental Backing Track] is an English language song and is sung by Original Backing Tracks. Undun (In the Style of Guess Who) [official Instrumental Backing Track], from the album Karaoke Hits: Classic Rock, Vol. 6, was released in the year 2013. The duration of the song is 3:29. Download English songs online from JioSaavn.