Harmonies, Similar or different?

 In Seized and Devoured the harmonies are mostly dissonant and though the power chords during the second half are major. The song itself doesn't have specific key though it changes often so that you can't place it in a main scale very well. But because it is death metal the dissonance is a big thing.

Concerto No. 3 has a main key of D minor and sports a three movement body. The first movement is in D minor, the second F sharp major/D flat major and the final a D minor to D major combination. The harmonies are more important in this piece because it has more instruments and thus more notes being played. Though it is minor it also has major themes and motifs giving it variety.

So the harmonies are different with Rings of Saturn favoring a dissonant and free play key and Rachmaninoff using his keys and chords.