Undertale (2015) is an RPG developed by Toby Fox, who is also the composer of the music. At first glance, Undertale resembles quite a few other games that came out around the same time which have nostalgic pixilated visuals and 8 bit sounding music; one such game being Shovel Knight (2014). However, as you progress through the game, it becomes clear that Undertale is a parody of these old-style RPGs where the player goes around the world, defeating the “bad” characters with very little consequence for themselves.
If anything identifies that a lack of consequence is not the case in Undertale, it is the music. Character themes occur for almost all enemies seen in the game, except for random encounters although these still have been given a personality of their own. Each theme is unique to the character and boasts interesting and complex rhythms and melody, which are transferred between the character it belongs to and any character it has a relationship with. For example, Toriel and Asgore share similar rhythmic traits in their melodies, as they are ex husband and wife. This adds a new level of emotional baggage for the player, as it is very likely that, if unaware of the pacifist route, they killed Toriel at the beginning of the game only to find her relationship with Asgore at the end.
Undertale creates these links between the characters in the game world, to cause a sense of being for everyone in the world and the player. If a player is unfortunate enough to decide to take the genocide route, then they will notice that, once all characters have been defeated by the player in an area, the music will take a negative appearance. The music slows down considerably, resulting in long reverberated drones which give the area an uneasy feeling appropriate to the genocide route. If any game can accurately represent its game world and inhabitants through musical material, Undertale is one of the best.