Telephone's Theme

Telephone's Theme is a song from the Octo Expansion. It is, as the name suggests, the theme for the Telephone, or Commander Tartar (as the latter, an alternate version of this song is used instead).

Description
The full version of the song plays when interacting with the Telephone for the first time in the Deepsea Metro. When the player enters a cutscene with the Telephone after this, a different version of the theme plays with fewer instruments and a shorter loop. Interacting with the Telephone when not in a cutscene does not play the track.

The song starts with strange sound effects, presumed to be what the Telephone sounds like. This song has heavy use of synthesis instruments, however, it does seem to use a trombone as well as percussion. Various radio signal sounds are heard, which are also used as an instrument to play the main melody throughout most of the track. Throughout the track, the drums play a constant, fast, repeating rhythm with the use of trills. Near the end of the loop, the drums are the only instrument to play, playing much more frequently and faster.

Actually it's Commander Tartar's Theme
This version is used when the Telephone, as Commander Tartar, reveals the NILS Statue. It starts with the same intro as the original, albeit each of its part is slightly delayed. The last part of the intro is warped. Then, some distorted, slowed down sounds play as the distorted intro plays multiple times.