The Genocide is a musical representation of the genocide route in UNDERTALE. The beginning represents the introduction when your choices first take root, and you meet Sans. The middle is when you kill everyone. The end is the manifestation of the black emptiness after you kill everyone, and the reset afterward. I know this should be really dark-sounding, but . . . I couldn't find a glitch sound to put in :(
@GamerellaYT Toby Fox - Inspiration