The Turret Opera is a piece of music featured at the end of Portal 2, where numerous Aperture Science Sentry Turrets sing the song "Cara Mia Addio," an Italian aria. "Cara Mia Addio" is an Italian aria, but it is not accompanied by official lyrics. Fans of Portal 2 with an understanding of Italian have both transcribed them in their original tongue and translated them into English. The song was composed by Valve composer Mike Morasky, but the librettist is unknown. Ellen McLain is the vocalist for the song, as she also voiced GLaDOS and the turrets. In an interview, McLain claimed that she "made up the words out of [her] bad Italian [...] on the spot".