What is it?
To fully understand the spectrum of adaptive music one must additionally consider the concepts of interactive music and dynamic music. For a musical piece for games to be fully interactive, it has to include a way for the player to involve in active control or participation in the system that is designed to be reactive. In other words, the player's input actively changes the output of the musical piece. This means that it is necessary to distinguish between three forms and degrees of interaction in music, namely: reactive, adaptive, and fully interactive. When the music is merely reactive, the music plays in a similar fashion and without variance every time that the player commits a non-musical action in a certain way. The simplest form of this style can be found in early games like Final Fantasy or Super Mario Bros., in which the music fades out and in between two scenes, worlds or levels. Dynamical soundtracks adjust their volume to the other game sounds and effects.
By definition, the term adaptive music refers to that kind of background music that interacts with the events that occur in a given game. The music is actively modified based on the actions that the player makes. There can be changes in the rhythm, volume, or tonal structure of the musical piece. It can help you to grasp if you are winning in a game, going the right route, if you made a notable hit, or for example how your physical condition is at a given moment. Adapted in an elementary style in the 1981 video game Frogger by the renowned Japanese video game corporation, Konami, this form of music has ever since become an essential asset in the toolkit for video game composers. In this early example, as heard from below, the music changed quite unexpectedly when the player got into a safe point in the game.
The fully interactive music happens solely then when the impact on the musical level is directed by the intentional action within a game. There is a reciprocal relationship between the music and the player, where a certain action leads to a given sound. The most recognizable example of this can be found in games like Guitar Hero or Rock Band, in which the player's active input results in a musical output. Thus, the certain action is either repeated in the same manner or corrected based on the audible result. Fully interactive music can also only be present in some parts of the gameplay, like in small mini-games found in Ocarina of Time or Wind Waker, which both belong to Nintendo's Zelda series.
Following this, the most notable games that used this compositional technique in elementary and continuously evolving forms were amongst others: Wing Commander (1991), Monkey Island 2: LeChuck's Revenge (1991), Grim Fandango (1998), Skies of Arcadia (2000), and role-playing games like Elder Scrolls III: Morrowind from the year 2002.
Frogger
iMUSE
Lucasfilm Games, a video game licensor that was established in 1982 by the world-famous movie director George Lucas, was also behind the release of the before-mentioned Monkey Island 2: LeChuck's revenge. With this game under construction, the composer named for the work, Michael Land, started to rethink video game audio in the sense that the game audio would seamlessly match the visual action happening on the screen. Alongside another Lucasfilm Games composer, namely Peter McConnell, he advanced to create a system that allows the composer to set the mood through music keeping in mind the events of the game. Hence iMUSE (Interactive Music Streaming Engine), was born in 1991. To level the differences of personal computer processing speeds of that time, the iMUSE played back abbreviated or prolonged sections of the music while it awaited for the key events to take place inside the drawing engine. The music can consist as well of a database of music loops, cues, and transitions, which play in a varying manner during the gameplay.
Monkey Island 2: LeChuck's Revenge
Composition Techniques
On the most fundamental level, there are two techniques for the composers to utilize to create a soundtrack for the game that is truly adaptive. These are horizontal re-sequencing and vertical re-orchestration. Horizontal re-sequencing allows the use of pre-composed segments of music to be reorganized considering the choice of the player, where they go in a storyline, or the environment. An elementary form of doing this is just to produce a crossfade between the two musical cues. This means that when the setting changes, the first cue is faded out and the second cue faded in. If the composer wants to do the shift more subtly, she can use a technique called phrase branching. This means that the next segment does not begin until the ongoing musical phrase is concluded. A yet more advanced technique is called dedicated transitions, which simply means that when there occurs a switch across various segments, then also the transitions in the music are triggered.
Vertical re-orchestration, on the other hand, is a technique that underlines the change in the scenario of the gameplay and narrative. As a specific task is being completed, or when the narrative changes, then also the music seamlessly alternates between different segments or different versions of the musical piece, and by that expressing the exchange in the scenario. The exchange, also known as code-switching can be distinguishably found in the game Faster Than Light, in which the music has different soundtracks for exploration and battle. This is also known as soundtrack switching and can also be found in a more sticking-out manner in the Super Mario series, whenever invincibility is gained by capturing the gold star and producing an abrupt change in the music. Another form of the vertical re-orchestration is just adjusting the tempo. In Mario Kart, when the player approaches and finally reaches the chequered flag, the tempo of the piece has accelerated in a significant amount. In this latter way of making transitions is present a re-sequencing technique called 'stinger' transition, which allows a smooth transition to the faster tempo and thus creating a flow from the slower sequence on the second lap to the faster one on the third lap.
Mario Kart DS: Cheep Cheep Beach
Other approaches to adaptive music
Algorithmic music
An example of not having a pre-composed score for games, but that the content is generated during the playing, is Spore (2008), a game developed by Maxis and published by Electronic Arts (EA). It has in it an embedded version of Pure Data (PD), a music software used for creating interactive computer music and multimedia productions. The software creates the musical passages reacting to certain cues in the gameplay all throughout the game. The soundtrack found in Spore is also a dynamic soundtrack, where the individual sound elements comply with the impact effects. A similar kind of approach is used in the game Ape Out (2019), which integrates a jazz percussion soundtrack, which variates with the intensity of the gameplay and also reacts to the actions and movement of the player. There is an ingenious way in this game to link for example the placement of a certain area on a wall where the enemy is finished with a certain non-generic percussion sound that originates from the placement of the drum or cymbal in a real-world drumkit.
Spore
Games like Extase (1990) and Rez (2001), utilize sound effects that are triggered by the actions that the player performs. These are then automatically delayed so that they synchronize and blend with the background music. Hence an elaborate interactive musical landscape is created in which the player's gestures actively and without delay form, enhance, and impact the music. Adaptive music has also been used as a goal of the game. Such an example can be found in the 2012 released game Sound Shapes, in which the soundtrack intensifies to indicate that the player is doing well in the game.
Sound Shapes
Summary
In adaptive music, which is mainly present in game music, although there is a rich abundant tradition of it also found in classical music, the different versions of the musical piece are affected by the player. The player gives instructions for the system to operate by. There is a set of input parameters, for which the precise timing, sequence, quantity, presence, and values are those that in varying combinations determine the output of the system. In the piece, however the traditional, or stylistic coherence and organization are not compromised, but they are the utmost priority. These are pre-determined by the composer. Adaptive music allows thus a high form of interaction with the game in which the user interaction molds actively the content of the musical output. Adaptive music performances are flexible and all of the respective expressions depart from one another making it a creative tool for composers as well. It has somehow an intricately unorganized, but at the same time undisputable character to it, because when the input of the parameters matches the previous input, also the output is exactly the same. The performance of the generative system is nevertheless directed by aesthetic principles, which are determined in advance by the composer of the musical piece. The traditional way of composing linearly is profoundly present, despite the seemingly randomized nature of the music.
References
Adaptive Music. (2021). Retrieved April 13, 2021, from
https://en.wikipedia.org/wiki/Adaptive_music.
Aska, Alyssa. (2017). Introduction to the Study of Video Game Music. lulu.com.
https://www.lulu.com/.
Brachetta, Guillermo. (2021). Musical Dice: A new take on Mozart's game. Retrieved from
https://gbrachetta.github.io/Musical-Dice/
Clark, Andrew., (2007). Defining Adaptive Music. Retrieved from
https://www.gamasutra.com/view/feature/1567/defining_adaptive_music.php?print=1.
iMUSE. (2021). Retrieved April 13, 2021, from
https://en.wikipedia.org/wiki/IMUSE
Noodle. (2019, July 7). Adaptive Music (In Gaming) Is Amazing [Video]. YouTube. https://www.youtube.com/watch?v=yLd5wmBNCBM
Wright, S. T. (2019, May 27). How 'Ape Out' Creates a Soundscape Worthy of Smashing. The Independent Variable. https://variety.com/2019/gaming/columns/how-ape-out-creates-a-soundscape-worthy-of-smashing-1203150773/
Other Games with Adaptive Sound and Music:
Otocky (1987) by Famicom
The Mark of Kri (2003) by San Diego Studio
Rainbow Six 3 (2003) by Ubisoft
The Lord of the Rings: The Two Towers (2002) by Stormfront Studios
Halo Series (2001- present)
Guitar Hero Series (2005- present)
Portal 2 (2007) by Valve
Civilization VI (2016) by Firaxis Games
The Legend of Zelda: Breath of the Wild (2017) by Nintendo
Uncharted 4: A Thief's End (2017) by Naugty Dog
Red Dead Redemption 2 (2018) by Rockstar Studios
Devil May Cry 5 (2019) by Capcom
Examples of adaptive classical music:
W.A. Mozart: Musikalisches Würfelspiel (1792).
Karlheinz Stockhausen: Klavierstück XI (1953).
Earle Brown: Available Forms II (1965).
