"So Sad" is the debut single recorded by German band Gregorian. It was written and produced by Frank Peterson, and is from the album Sadisfaction (1991), on which it appears as the third track. The song is composed of Gregorian chants using biblical verses while in the chorus a woman is asking Jesus Christ why she is so sad. In the music video, she first enters a church, then becomes a nun. The song was included on Gregorian's best of compilation titled Best of 1990–2010, released in 2011, on which it appears as the first track. It became a hit in France and Portugal.