Music of the Toho scifi films

The majority of the scores for the Toho scifi films were composed by Akira Ifukube. Here is a summary of the major themes and where they appear.

Godzilla March

First appeared in Gojira. A heavily string based piece.

Kaiju Daisenso March

First appeared in Gojira, then 1959's Battle In Outer Space, before being truly refined for Invasion of Astro Monster in 1965(during the scene where the A-Cycle Light Rays are used).

Requiem

This dark theme appeared in almost all Ifukube sci fi scores in one way or another.

Battle theme

First used in 1957's Earth Defence Force/The Mysterians. Returned in 1991's Godzilla vs. King Ghidorah during the scene where M-11 gets into a gunfight with the Futurians.