It's hard to imagine video games without music. From the jazzy beeps and boops of the original Mario theme, to the little chirps and fanfares played to reward the player for power-ups or small victories, music has been integral to video gaming.
When Rand and Robyn Miller were designing Myst, they initially conceived of it as having no music. Since the game took place on a series of islands with no people, the idea of having a soundtrack running seemed out of place. But after realizing how empty the world felt without it, they composed forty minutes' worth of music, and found it gave the experience much more texture.
So while game music may simply be necessary to break up an otherwise awkward silence, and provide auditory cues so the player isn't totally dependent on visual stimuli, it also serves an important role in setting the mood for the experience. Though sometimes muted out of annoyance or ignored out of habit, video game music is its own emerging art form, with interesting relationships to past musical styles.
The Super Mario Bros. soundtrack back from 1985 is probably the earliest video game music with widespread familiarity. Its basic melodies have been arranged for a good deal of the titles in the series, and given weighty treatment. But the original score—the jazzy overworld music, the underwater waltz, the dungeon theme, and the various fanfares—all total a mere four minutes and forty seconds of music. And that music was all Super Mario Bros. had, to endlessly cycle during any given part of the game. Later soundtracks grew much more elaborate as synthesizers and space improved, with Super Mario World having around twenty-seven minutes of music. The 16-bit era also saw soundtracks beginning to be taken seriously on their own and sold as albums: games like Donkey Kong Country and Chrono Trigger were released alongside soundtrack albums in the United States, and several role-playing games (RPGs) aimed for epic storytelling and scores.
By now technology and game budgets have reached the point where it can be practical to hire an orchestra or choir for a game soundtrack piece, commission an original theme song, or even license pop music for the soundtrack. Even the latest Mario game, in a series never known for its dramatic storytelling, has had a full two hours' worth of music scored for it. The game music scene is growing: companies have put out orchestral arrangements of originally synthesized tunes, a few video game concerts have gone on tour, and remixing communities have sprung up on the Internet.
With the video game industry outpacing movies for revenue and becoming a major cultural force, and with all the potential available to it, I think it's worth taking a look at what game music is, and how it necessarily differs from typical soundtrack fare.
To illustrate the difference between game music and other soundtrack forms, I'd like to begin by dividing game music into two categories: static and dynamic music. Static music most closely resembles other soundtrack work: it's a piece of music which can be determined entirely in advance, typically synced to a scripted scene. A soundtrack composer for a movie works off of a given piece of footage, and is left with the challenge of setting music to it. The resulting piece of music can be determined entirely in advance, and any factors of presentation are known in advance or irrelevant.
The second category of video game music is the unique one: it represents music which changes based on feedback from the player or the game's system as a whole. Rather than being a static track which plays through only once, accompanying a scene taking place on a fixed timetable, the piece has to be able to loop, resolve, change in instrumentation, or be triggered—all depending on what the player does. Video games generally make use of both static and dynamic tracks, and it's the uses of both I'd like to cover next.
Static Music
Anytime you place control of a scene in the hands of a player, you open up the possibility that the scene, and hence the music, may extend indefinitely. This scenario makes it very difficult to sync up the timing between the game's events and any static music written in advance. Hence, the most obvious application for static music in video games would be for scenes in which the player has no control: namely, game introductions, endings, and in-game cutscenes. A number of games engage in storytelling by taking control away from the player briefly and letting some pre-rendered cutscene play. Here, the music is subject to largely the same conditions as music written for a scene in a movie, in which the material to be accompanied is fixed in advance. A cutscene in a video game obviously may serve a very different purpose than a scene in the middle of a movie, but it shares the quality of being able to sync up the music to the development on screen much more precisely, and requires the player's focus rather than simply serving as background material for some other activity.
In addition to cutscenes, there's some limited use of static tracks for pieces set to run on a fixed timetable regardless of input from the player. If an escape scene is set to play until a timer runs out, that sequence could use a static track. So could any scene in which the player has some control but events proceed according to the same schedule regardless of input. For example, there are scenes in Half-Life 2 in which the player has limited control but dialogue and events continue at the same pace regardless. Similarly, the introduction to a specific boss battle in Chrono Trigger does not allow the player to scroll the dialogue at will; by means of this restriction, the text will be synced up with the music. And there are obviously situations in video gaming where the designers simply choose to play a track through once and ignore any concerns of responding to player input or synchronizing that track to events in the game.
Dynamic Music
Dynamic music is any type of music whose performance is dependent on feedback from the player or the system as a whole. As mentioned above, the most obvious application of dynamic music is to scenes that can extend indefinitely. A piece which may loop indefinitely is subject to a few constraints: it has to be able to transition smoothly from its ending to its beginning, which is why many such pieces begin with a brief one-time introduction to have a more natural opening to the piece. Such a piece will often lack a typical "resolved" ending, instead having to remain unresolved and always moving into the next section. When released with a soundtrack album, such pieces will typically be played twice through and then fade out.
Given how much gameplay a piece of music may be stretched over—a one or two hour soundtrack frequently being played over ten to forty hours of game time—a number of techniques for dynamic music exist precisely to prevent annoying repetitiveness. In particular, there are a number of techniques to ensure the player doesn't get turned off to hearing the same small introductory section of a piece over and over again. Games such as RPGs, which may have overworld music occasionally interrupted by battles, will often save the position in the song that was interrupted, so the interrupted piece can resume and the player won't be spending a disproportionate amount of time on the piece's introduction. Similarly, some games may choose a random position from which to start playing a song, randomly transition between different sections of a song, or have a number of different songs which can play for a given event.
Another technique to both prevent repetitiveness and make the game's atmosphere more responsive is to alter the instrumentation and aspects of the performance depending on the player's situation. In Mario Kart Wii, for example, a piece of music may play through continuously but become darker and more muted when the player goes underground. And in Super Mario Galaxy, an energetic, brassy track can turn into a distant series of plinks when the player goes underwater. As far back as Super Mario Bros., game designers have made use of changes in tempo, speeding up the music when the player is running low on time, badly hurt, or the action has intensified. And in the context of a game world, the music can also vary in volume depending on how close the player is to the source, allowing different songs to fade smoothly into each other.
In terms of style, some game designers try to reduce the perceived repetitiveness by using music that's light and ambient, so that over protracted periods it's easier on the ears than recognizable melodies would be. And one obvious technique to avoid overuse of music is simply to include more music in the game to begin with; thus, some RPGs have soundtracks in the three to four hour range, and Super Smash Bros. Brawl has a soundtrack in excess of eight hours.
In addition to pieces which may loop indefinitely, I'd also like to place in this category the previously mentioned examples of brief fanfares, or informational cues. These could be thought of as extended sound effects that last at best a few seconds, such as the triumphant fanfares of solving a puzzle or opening a chest in the Zelda games, or the energetic Starman music of the Mario series. Since they often play on top of, or only briefly interrupt a normal piece of music, I'd characterize them as dynamic music, dependent on player feedback.
One last note is that while many of the features of dynamic music would be impossible for typical soundtracks, they have been utilized in live music historically. Music played for an audience may be expected to continue for an unspecified period of time or make tempo changes on the fly, and bands may play rimshots or other cues in response to events. And it's also worth noting that tasteful use of repetition is not unique to dynamic music: the second movement of Beethoven's Ninth Symphony contains a number of small sections which repeat, and it approaches a resolution six minutes in—only to return to the beginning of the piece, build back up to the resolution approached earlier, and conclude itself. A certain amount of repetition is necessary for musical themes to stick. A soundtrack which was composed on the fly without ever coming back to a previous theme would likely leave the listeners feeling like they couldn't get a handle on it, and they would have a harder time forming associations with the music and what was happening.
Video Game Music and Gameplay
So far I've largely talked about the technical concerns that drive many of the features of video game music. The last topic I'd like to cover is how the various types of gameplay affect the music stylistically.
Another important difference between video game music and television/movie soundtracks is that game music is not written to accompany the spectacle of some scene being passively observed, but to accompany an activity. In this regard it shares some features with dance/exercise music. Under most circumstances the music is not meant to demand full attention, or engage the player in watching a scene, but instead to fit with an activity. A track from a video game is not meant to be experienced in the context of an album or a live orchestra performance, but alongside a unit of gameplay.
Thus, a major determining factor for a piece of game music is the type of gameplay it's meant to accompany. In addition to conveying mood and contributing to setting, it also has to feel appropriate to the sorts of activities expected of the player. As mentioned before, during in-game cinematics or sequences in which the player has no control, the music operates under largely the same conditions as a piece scored for a movie soundtrack; the player is simply expected to be a passive observer and stay entertained enough to not want to skip ahead.
The introductions and endings to games, while also non-interactive, usually operate a little differently. While cutscenes follow more standard storytelling conventions, introductions are often a sample of the game's content and gameplay, designed to prime the player's enthusiasm for getting into the real thing. Introductory music can often be more self-aware and draw attention to itself; for example, the introductory theme to Smash Bros. Brawl features a full-on chorus with lyrics that might be distracting in other contexts. Endings, on the other hand, often serve to wrap up and summarize everything that the player has experienced, and frequently turn to a medley of the game's various themes.
In contrast to Brawl's attention-grabbing opening theme, the game's menu features a much more reserved arrangement of the same theme without lyrics, not nearly as dramatic or rushed. Menus, world maps, and pause screens all give the player a chance to explore some interface, and configure things to his or her liking, before moving on to the actual game. It's meant to be unhurried and the music is correspondingly less stressful. The player's taking a break from the main action, and while the music may be anticipatory, it isn't meant to jolt its listener out of that rest.
The bulk of video game time, and hence game music time, is spent in an action-oriented, reflex-intensive environment. For platformers, this can mean jumping from ledge to ledge and dodging or attacking enemies; for racing games it can mean soaring through a track at high speed; and for first person shooters it can mean being armed with a weapon and chasing down or being chased by hordes of enemies. The music for such types of gameplay is typically fast-paced, and conducive to quick decision-making and precise timing. With a good soundtrack, the player may get the sense of keeping pace to the music, and racing forward along with it.
Some additional types of gameplay that game music is often written to accompany are puzzle-solving and exploration. Puzzle-solving places different expectations on the player than most reflex or timing-based skills do: for puzzle-solving, the music has to be appropriately musing and intense, without being too stressful or distracting the player from thinking clearly. And the needs of an exploration sequence stand in contrast to music set to arcade action as well: for exploration, the soundtrack is more often meant to provide character to a setting and keep the player curious as to what awaits discovery. Games such as the Zelda series balance goals of exploration and fighting by having the music transition into a faster-paced, darker theme whenever an enemy draws near, but having the music revert to a more scenic piece when the enemies are killed or are far enough away.
Some games also explicitly include music as part of the gameplay by asking the player to keep pace to a song being played, help compose or follow along with a song being performed, or perform rhythm matching for games like Dance Dance Revolution or Guitar Hero. In such cases, the music obviously needs a strong beat the player can keep up with, and in the case of rhythm-matching games, they're made a lot simpler if they draw from musical sources that the player is already familiar with, such as licensed pop songs. And concerning the use of popular music, it's certainly true that a previously composed piece of music can be used as the soundtrack for any of the styles of gameplay mentioned. But even if concerns relating to gameplay did not factor into the composition of the music, they still apply to the appropriateness of the music being selected.
One final illustrative example of music as used in video games comes from the Final Fantasy series. While the titles are almost wholly unconnected in terms of plot, they do share many conventions between them, including the re-use and development of musical themes. Many of the games make use of an arpeggiated piano piece in their opening, draw on the same victory fanfare, and frequently remix the series's Chocobo theme. But one of the most interesting things about the music of the series is its use of character themes. Employing a device dating back to Wagnerian opera, the games often set up a simple melody to serve as a leitmotif for a character, to mark his or her presence in a scene and describe him or her musically. Such a theme might show up repeatedly in a story, and be worked into different pieces. It serves as a way to tie the music to the story, and particularly to the player's intermediaries, the game's characters.
In its earliest days, on top of the challenges of composing appropriate music to accompany varied and unpredictable gameplay, game music was subject to numerous technical restrictions limiting its quality and complexity. As technology has advanced, game music has reached the point where it's capable of all the fidelity of a typical soundtrack, and of having many more interesting adaptive features besides. As the medium continues to develop and consume an ever-increasing share of our auditory lives, it will be interesting to see it adapt and continue to carve out its own musical niche.