Listen to Gregorian Chant: Iam lucis  online. Gregorian Chant: Iam lucis  is an English language song and is sung by Stephen Cleobury and Westminster Cathedral Choir. Gregorian Chant: Iam lucis , from the album Sacred Chants, was released in the year 2017. The duration of the song is 1:33. Download English songs online from JioSaavn.