If put in these reductive terms, Harmony in a sense has the best sound quality of its peers--the persistent audio fuzz prevalent in Circle and Aria doesn't exist in it, with every note played as clearly as can be.
Adding on to this, there is a
lot that Harmony does with its music that would have been nearly impossible with more elaborate samples. Harmony's music is dramatic and dynamic in a way that neither Circle nor Aria can replicate -- there are major changes in dynamics across every song, and while the lack of an obvious pop hook in the tracks compared to the way Circle (aided by reuse of many of the series' most popular tunes) and Dawn (with Masahiko Kimura directly citing the MJ-inspired arrangements for Dracula X he had a hand in) means the songs aren't particularly hummable, there's a sophisticated, dare I say
proggy, approach to how the songs work. Any lack of timbral texture due to the small set of sounds the game uses are more than made up for by the way that rhythmic patterns phase in and out with each other, chords meander and return to key centers, and instruments fade in and out. There is much for the ear to latch on to here, and the songs do lend themselves well to the sorts of repeated listens that exploratory platformers of the Castlevania variety encourage through backtracking, grinding, and exploring each nook and cranny on the map.
I actually think the worst of the GBA soundtracks is Aria, and one of the reasons (along with a somewhat stilted translation for the story) that I don't muster the same level of enjoyment for the game that much of the rest of the internet does. It is a very impressive marvel and does a lot to bring the mechanical extravagance of SOTN to a much more limited system, but those same limitations make the way the game presents itself that much less engaging, and it is definitely in the music that I feel this the most. Unlike with Harmony, tracks are a lot less dynamic, and tend to drone. People in particular favor the Chapel music, but I find it exhausting to listen to with its unrelenting organ arpeggios; even in an
idealized form free from limitations of mixing guided by CPU interrupts, the song feels like a shorter passage in a larger track that is about to resolve, but never does. Tracks keeping both a consistent level of harmonic tension and volume lends itself to a soundtrack that feels like it is constantly spinning its wheels in place. The only song that I think suits this kind of structure is
the floating gardens; the basso ostinato and harmonic developments that never really resolve in traditional ways produce a track perfect for an area with confusing, nonlinear structure where it's not clear when the player is going where they want to be and could be getting closer or farther away from their goal of the next areas. Despite this, the track almost never shows up in larger soundtrack compilations.
If there is one criticism to lay at the hands of a sound design like this, it is that games with a more pop sensibility to their music tie in more strongly with the notion of the average videogame as a dance performed by a player's hands or fingers. Other games' tracks can be more or less suited to the inherent tempo of their stages. While Harmony's tracks all have fixed BPM, the way those beats get expressed as either more languid legato passages or more abrupt staccato breakdowns changes across every track, leading to very different feels that may or may not be immediately as consonant with the game's activity.
This is one thing that Aria does better than Harmony simply by virtue of the much simpler tracks. The argument is all but explicitly stated in the game itself, really. The Underground Reservoir and the Colosseum, as in SOTN, contrast with the former as a large area built around exploring and experimenting with abilities and transformations and the latter a compact area with layouts built to serve mainly as monster closets with a focus almost exclusively on combat. Here, though, their music shares a similar theme with both having variants, and those variants being designed explicitly to suit those areas.
The former is an almost ambient piece that shares some unusual harmonic development that modulates at several places but has sections that build in intensity and eventually resolve themselves in a more satisfying way than the Chapel's music does; the song's loop going back to a basic string sweep and melodic percussion arpeggio and nothing else gives it a return to rest that makes it easier for one's attention; if the chapel is an unending angry rant covered in spittle, this track is a guided meditation.
The Arena speeds up the melody's pace, does less modulation in-between phrases (there is only one modulation up a half-tone about halfway through the song), and uses chords much more common to the series. It is a faster song, easier to understand due to its reliance on those common chords, and does not wander anywhere near as much; its repetitive break strains mirror the somewhat grindy nature of the combat segments the area holds.
