Listen to Variations on a Theme of Sor, Op. 15 online. Variations on a Theme of Sor, Op. 15 is an English language song and is sung by Rovshan Mamedkuliev. Variations on a Theme of Sor, Op. 15, from the album Rovshan Mamedkuliev Guitar Recital, was released in the year 2013. The duration of the song is 8:45. Download English songs online from JioSaavn.