Octoling Rendezvous

Octoling Rendezvous is a song performed by Turquoise October.

Description
Octoling Rendezvous, like many Turquoise October songs, is an electronic song, featuring many chiptune influences and Octarian-sounding vocals. It plays during most levels with Octolings, such as every level with Mini Zapfish. In the Octo Expansion, it often plays in levels based off Ranked Battle modes. The "regular" version is only heard once an Octoling notices the player and starts attacking them; otherwise, the "unnoticed" version plays instead. However, in the Octo Expansion, this version plays all the time, with no change regardless. This version is the one used in Squid Beatz and Splatune.

Octoling Rendezvous (Unnoticed)
This version removes the singing vocals, drum track, and "bubbly" sound effects, for a less intense version of the original. It plays when the Octolings cannot see the player and is the version that plays at the start of every level. In the game's files, this is the original version, and when Octolings are sighted, an additional track is played concurrently containing the missing features to bring it back to the original version. It is possible to extract the isolated track from the game.

Octoling Rendezvous (Final checkpoint)
A distorted and more frantic version of the song plays, with a higher pitch and more emphasis on sound effects, near the end of each respective level. In Splatoon 2, this starts playing after collecting the penultimate Mini Zapfish and being spotted by Octolings results in no further change in music at this point.

Trivia

 * This is the only song that plays unchanged in Splatoon, Splatoon 2 and the Octo Expansion.
 * Only the more intense version plays in the Octo Expansion because it's impossible to go "unnoticed" in those stages.
 * It could also be just because Agent 8 is an Octoling.

Etymology
Octoling Rendezvous refers to a meeting with an Octoling, although in a much more polite situation than what actually occurs in-game.