Ace Combat 04: Shattered Skies was the most successful game in the flight simulation series both commercially and critically. Though it featured many changes from its predecessor, one of its most significant and influential was the score, which focused more on orchestral epics than futuristic electronica. The resultant soundtrack was ideal for both representing the WWII-influenced storyline and the intense combat scenes. While returnees Tetsukazu Nakanishi and Hiroshi Okubo crafted much of the soundtrack, new composer Keiki Kobayashi made the most defining contributions. While maintaining the flavour of a Hollywood spectacle, they packed it with plenty of diversity too, including plenty of rock influences, electronic undertones, and even a vocal closer. But before looking at that, let's get started...
Despite its brevity, "Shattered Skies" is an effective title theme for the game. The opening lyrics "I have so far to go" establish the concept of facing war while exposing a motif featuring in the ending vocal theme. The rest of the theme is instrumental, but hints further at the content of the score with the string-based rendition of its main theme and the use of militaristic percussion parts. Tetsukazu Nakanishi reinforces the main theme with several of the electro-acoustic hangar themes, "Gateway" and "Stardust", that appear throughout the soundtrack. He subsequently lets the theme take centre stage once more with interplay between a solo trumpet and a string section on the first stage theme "Sitting Duck". Although a good composition, many will find the orchestration lacking compared to the epics of Ace Combat 5; the forces sound synthesized despite the high quality mixing and they are thinly supported by atmospheric drum kit beats and electronic frills. Nonetheless, the composition still sounds fully fledged overall thanks to the introduction of an extended electric guitar solo and more punctuated accompaniment from the 1:37 mark. This section usually coincides with getting to the centre of the action in the game so the characteristically long development works spectacularly in context too.
Although most of Nakanishi's mission themes are built on the same elements as "Sitting Duck", there is a lot of variation in the way the forces are used to complement the game. In "Imminent Threat", plenty of tension is created during the mission to take down enemy bombers through the contrasts of formidable brass leads and the occasional semi-playful marimba motif. "Invincible Fleet" reflects the pressure of conducting a mission under a time limit with several layers of development; following the atmospheric introduction, the theme gathers energy by building upon an unresolved string motifs to explosive results around the 2:30 mark. The aquatic scenery is also complemented by a lot of the electronic backing work and a quiet string-led interlude before the loop. Of the more upbeat tracks, "Comona" is the closest the soundtrack comes to a straight-out rock jam with Nakanishi's electric guitar improvisation juxtaposed with energetic strings. Later on, "Tango Line" makes traversing through canyons all the more fun with its ethnic tuned percussion work and temperamental orchestration. "The Northern Eye" and "Escort" also ensure periodic reinforcements of the main theme during the game, the former one of the most epic cinematic tracks of all and the latter adding to the weight of an enduring mission.
Although Nakanishi is by far the major contributor to the soundtrack, the other composers make their influence known in the game. Keiki Kobayashi's "Blockade" is immediately refreshing with its maturer orchestration and richer harmonisation compared to Nakanishi's tracks. He builds so much suspense during the early part of the mission with the repetition of a rhythmically compelling string figure before passionately releasing it all with a beautiful violin solo from the 2:40 mark. "Operation Bunker Shot", on the other hand, features tremolo strings throughout to reflect continued agitation in the face of enemy forces and demanding objectives. Kobayashi's renditions of the main theme here are momentous here and really embellish the feel of a war epic. Hiroshi Okubo's "Breaking Arrows" and "Breaking Arrows #2" are successive tracks to represent an elite enemy force in the game. Both are slow-building percussive tracks that generate plenty of tension in the game, but are monotonous on a stand-alone; they're certainly stronger compositions than Nakanishi's similarly toned "Stonehenge" tracks, yet are more obnoxious on a stand-alone basis since they dominate a whole nine minute section of the soundtrack. Fortunately, Okubo manages to redeem himself with his atmospheric soundscaping in "Lifeline"; every bar makes a big contribution to the overall atmosphere in this one.
Moving to the end of the soundtrack, Nakanishi's "Emancipation" is easily the most poignant mission theme on the soundtrack. Most gamers will member how this jazz-orchestral track worked beautifully with the nighttime visuals during the mission to liberate a city from enemy rule. "Whiskey Corridor" and "Farbanti" recapitulate the main theme for the so-called final missions, the former a high energy orchestration and the latter supported by grungy rhythm guitars. Of course, the game didn't quite end there and, after three ambient scene-setters, Kobayashi returns with the true final mission theme "Megalith -Agnus Dei-". This track has achieved iconic status within the popular video game scene over the years for good reason — it's a seven minute orchestra and chorus colossus that, despite a few clichéd features, features tremendous production values. It inspires so much emotion during its playtime, simultaneously enpowering yet intimidating listeners with its glorious melodies and unrelenting development. Okubo's vocal theme "Blue Skies" is a commendable if out-of-place effort featuring soothing jazz vocals from Stephanie Cooke and modern minimalistic accompaniment. Following a couple of likely unused rock-based stage themes, the soundtrack ends with a series of simple but touching acoustic guitar compositions and arrangements from Katsuro Tajima used during the cutscenes in the game.
The Ace Combat 04 Shattered Skies Original Soundtrack represented a fantastic new direction for the series as it flew over to the PlayStation 2. The soundtrack is very effective in context for representing the wartorn battlefields, fast-paced flights, or even the various menu screens. However, it is also mostly a fantastic stand-alone listen thanks to the strong melodies, rich development, and stylistic diversity despite a couple of bumps along the way. The orchestral approach definitely seemed warranted for a war game and it was quite well-implemented overall, even if its sequel bettered it in this regard. However, perhaps the most defining tracks on the soundtrack are those that fuse orchestration with other elements, whether rock in "Sitting Duck", jazz in "Emancipation", marimba in "Tango Line", or chorus in "Megalith". This album is recommended for anyone who enjoys orchestral action music or liked the soundtrack in the game.