Interactive music

In video games, dynamic music (or adaptive or interactive music) is where specific events cause the background music to change.

Dynamic music was first used in the video game Frogger by Konami (1981), where the music would abruptly change once the player reached a safe point in the game.

After this, its next uses in major video games were Wing Commander, Monkey Island 2: LeChuck's Revenge and Ultima Underworld: The Stygian Abyss. It has since been used in such games as Mushroom Men and Guitar Hero.

Many of LucasArts' games used the iMUSE dynamic music system, from Monkey Island 2 onwards and including games like Dark Forces, Star Wars: TIE Fighter, Full Throttle and Grim Fandango. The iMUSE system is notable in that it segues seamlessly between different pieces of music rather than having an abrupt cut.

Later games which made notable use of similar dynamic music systems include the Deus Ex and Freespace series of games.

It is also a staple of the role-playing game genre, often being used to change the music when the player is in combat, such as in The Elder Scrolls III: Morrowind.

The music in video or computer games and certain films is meant to draw the audience through a storyline using two distinct techniques: horizontal re-sequencing and vertical re-orchestration. Horizontal re-sequencing is the method by which pre-composed segments of music can be re-shuffled according to a player’s choice of where they go in a storyline or environment. vertical re-orchestration is the technique of changing the mix of separate parts of an ongoing loop of music in relation to a player’s movement within the narrative of a game. Games, such as Halo 2, employ a mixture of these techniques in the creation of their soundtracks. Street Fighter II and Mario Kart DS are examples of games which change the music's tempo under certain circumstances.

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