Mr. Blue Sky

The fourth and last track of Concerto for a Rainy Day, on side three of Out of the Blue, written and produced by Jeff Lynne. Lynne told BBC Radio that he had shut himself away in a Swiss chalet to write the follow-up to A New World Record and came up with nothing during two weeks of dark mist. When the sun came out over the Alps, he wrote this song and thirteen others in the next two weeks. It is often described as the band's signature song.

The arrangement is called Beatlesque, resembling Martha My Dear and A Day in the Life, and its first four chords and harmonic rhythm match Yesterday. The piano and drum intro is borrowed from the Kinks' 1968 song Do You Remember Walter. The cowbell-like sound is Bev Bevan hitting a fire extinguisher. A heavily vocoded voice sings the title and, at the end, "please turn me over". Kelly Groucutt's 1983 lawsuit claimed he had written the middle section without credit.

Afterlife

It was the second single from the album, reaching number 6 in the UK and 35 on the Billboard Hot 100, and promotional copies were pressed on blue vinyl. AllMusic's Donald Guarisco called it a miniature pop symphony. Ultimate Classic Rock ranked it ELO's best song, and Classic Rock History and Stereogum both ranked it second. Lynne named it among his nine favorite ELO songs in 2022.

In 2012 Lynne re-recorded it in his home studio for Mr. Blue Sky: The Very Best of Electric Light Orchestra, without the orchestral ending. An animated video directed by Michael Patterson and Candace Reckinger, with animation by University of Southern California students, appeared that year.