A demo for the main melody was first heard in an impromptu demo live stream hosted by the band, and was eventually released as part of Demos Vol. 1: Music To Kill Bad People To. The demo version consists of a jam on the main theme and was later split into three songs. The tone is most like “Sketches of Brunswick East I”. On April 3rd, 2017, a user named “Blinky Bill” posted a link to a playlist of demos on Soundcloud called “Polygondwanaland” in the Facebook King Gizzard fan group. Alongside demos for “Crumbling Castle” and the “Polygondwanaland” suite, were two tracks called “Spanish,” each one given a different number. “Spanish I (1)” was the fourth song in the playlist. While the Polygondwanaland demos were ripped by fans, this track wasn’t, leaving it a mystery as to what exactly it was. That said, we can infer that it was “Sketches of Brunswick East I” due to the connection with the album title inspiration, Sketches of Spain by Miles Davis. “Blinky Bill” was later revealed to be Stu, who requested that all of the demos not be leaked as they were accidentally shared to the public group.
The studio version was played by Alex Brettin (piano), Cavs (drum kit 1/snare brushes/maracas/floor tom/vibraslap/bongos), Cook (guitar) and Stu (bass/electric piano/flute) and released on August 18th, 2017.

King Gizzard has never played the song live based on available data though setlist.fm indicates the song may have been played a number of times by Mild High Club.