Response to Cold Earth:
The chord progression for this song is F5, A5, and B Minor on a loop. The synth pads open with these notes (at about 68 BPM):
At 0:42, a synth bass comes in:
At 1:03, we get the first instance of a melody (the repetition of which at 1:11 is similar enough that I haven't bothered to notate:
They don't all mix until 2:28:
The rest of the song is mostly percussion and various atmospherics (the voices, the random sound effects, the white noise).
The reason these chords give the song such a distinct sound is their sparseness. The F and A chords don't contain a third, which makes their tonality ambiguous (could be minor or major?). However, in the context of the song we hear them as F Major and A Minor because they are next to each each, which would usually indicate the key of A Minor. The only problem here is the B Minor chord: it contains an F# which doesn't fit in A Minor, especially not when it was an F natural earlier for the F5 chord. The unexpectedness of the B Minor chord, which would be considered a minor ii in A Minor, is certainly exploited by BoC. At 1:00, 1:21, 1:42, 1:54, 2:05, 2:25, 2:46, and 3:07, the B Minor chord plays and three different things happen (not every time). The first is that the percussion drops out momentarily (creating a break), the second is that a high G note plays, which reinforces the key of A Minor but clashes against the B Minor chord, and the third is that a random sound effect plays, usually some type of clang or rattling noise.
The interesting thing is that after the 2 measures of B Minor, the song loops back to the F5, a chord that is a tritone away (the tritone can be heard clearly in the bass). This interval, also known as a diminished 5th or augmented 4th, is generally considered the most dissonant-sounding in Western music. To see for yourself, try playing a F and B next to each other on your preferred instrument. This tritone-relationship, and the presence of the B Minor chord in a key that shouldn't include it, are a great example of how BoC use unexpected chords to give their songs a unique feel. In fact, Tangerine Dream also used the B Minor against A Minor sound in their song White Eagle (
https://youtu.be/mTJYvj5lE4E?t=33m47s), which I wouldn't be surprised if BoC had heard and possibly drawn inspiration from.
Hopefully that gives you an idea of how Cold Earth pulls off its distinct vibes!