I've been learning some Christmas carols on the guitar and I noticed that the chord structure they have is very different from what I can usually see in popular/rock music.
I noticed that the melody that is meant to be sung is reflected (along with it's pitch) by the chords following this melody.
That feels like the chords don't function here as an accompaniment to a melody and does not provide it's standard function, which is tension and release, but rather follow the sung word changing to match higher or lower pitch that is currently being sung.
So instead of chords being its own thing and melody its own (in a reasonable, consonant way, of course), the chords seem to be the melody itself. If you didn't sing the song and just played the chords, you could pretty much imagine the right words In your head.
It feels different than a typical chord progression I'd sing a song along with. Is there a name for these two approaches of composing?
And more importantly, what would we call the function of these chords that follows the melody by it's pitch more than by a sense of building release and tension? Are they for an accompaniment, or sometimes maybe it's just ok to follow the melody with chords pitch like and by the function they stand for in the scale?
The video (it's a tutorial in Polish, it's a Polish Christmas carol):
I'm talking about this exact moment (chords changing rapidly trying to match the singing voice) and pretty much entire song in general. The song starts with V (Gmaj) and I believe the entire song is in C so it's already pretty unusual from a popular music point of view to start a song from V chord.
And that's what I mean by "more popular approach to chords accompanying melody":