Goodbye Blue Sky is a song by the British progressive rock band Pink Floyd. It was released on The Wall album in 1979. The Future Sound of London covered it with the title "Goodbye Sky". Armenian-American alternative metal band System of a Down has also covered the song live on at least four separate occasions. Ann Wilson, lead singer of Heart, recorded a cover version of this song for her 2007 solo release Hope & Glory with her sister, Nancy Wilson.
The piece is fairly quiet in terms of dynamics, although the tone does change several times throughout. It is 2 minutes, 48 seconds in length. In the introduction section, there is an innocent childish voice stating, "Look, mummy, there's an aeroplane up in the sky!". This particular section is calm and tranquil initially, but quickly grows more sinister in tone. Shortly after the tone change, the main lyrical section commences. The song bears some similarity to Ummagumma's "Grantchester Meadows".