Listen to Who Could Have Known (Lounge Piano Mix) online. Who Could Have Known (Lounge Piano Mix) is an English language song and is sung by Erotica. Who Could Have Known (Lounge Piano Mix), from the album 50 Relaxation Essentials - Relaxing Collection, was released in the year 2010. The duration of the song is 3:11. Download English songs online from JioSaavn.