The earliest mention of the song was on November 16th, 2010 when it was uploaded to the band’s Soundcloud page. A CD single for “Sleep” and “Summer!” was released sometime that same year with a fold-out sleeve depicting King Gizzard and a Lizard Wizard. It was added to the ASCAP ACE Repertory before the release of Float Along — Fill Your Lungs in 2013 but wasn’t released digitally. In a 2015 Reddit AMA, Stu explained that the CDs were made for friends and that he was unsure what happened to them. He also said that, at the time, he had no intentions on re-releasing the singles. Despite not releasing the songs officially, “Summer!” floated around on unofficial bootlegs. At the end of 2017, the lyrics of “Summer!” were adapted for the Gumboot Soup song “Muddy Water.” In a 2020 Reddit AMA, the band were asked multiple times to release the early material as part of a compilation. On December 14th, they tweeted that they were looking for high quality FLACs of the first two singles. This would become Teenage Gizzard, released on Christmas Day, 2020. “Summer!” would be the fourth song on the album.