actually, after listening to the recordings, yes, that is the theme of Mr. Halo
all seriousness aside, I have worked a bit with the Doom (2016) soundtrack, and they reworked the first level’s soundtrack from Doom (1993)
don’t know if I did it right or not, but it’s better than nothing.
one big difference, in Doom’s case, the later one was inspired by the original, not the same work in my humble opinion though… in the two examples you gave sound like they might be almost the same work. at least without a super in-depth listen, maybe the “lyrics” are different between versions or something?
to my understanding, a leitmotif is like the Shire leitmotif from Lord of the Rings (the melody the flute plays at the very beginning of this recording)
it’s used throughout the whole Lord of the Rings soundtrack, often on different instruments, but still the same general melodic line in most cases.
another example would be the Imperial March from Star Wars. they use the first few lines as shorthand for, “hey look, it’s the Imperials!” or “hey look, it’s Darth Vader!”, and that way they can evoke the feeling of the Empire or Darth Vader in other scenes.
in other news, made a cool meme music discovery thanks to some random person in my YouTube recommendations… I found the “Oh no” song from TikTok:
this is the reason I’m taking so long sorting through my library… I find cool thing, I say “ooh, this needs to be in MusicBrainz”, then I add it and never make progress on my own library…