Your Best Nightmare

Your Best Nightmare is the 79th track in the Undertale Soundtrack. It plays during Photoshop Flowey's battle at the end of a Neutral Route. 
The song is composed of various parts. The first part consists of a dark tune that samples the melody from You Idiot. This plays only at the start of his battle and is not included in the loop. A distorted version of Flowey's laugh plays before the song alternates between two parts: variations on the first tune with a breakcore beat during Flowey's fight and variations of Your Best Friend during the encounters with the SOULs. Flowey's segments are followed by the sound of TV static as a SOUL presents itself.
== Trivia ==
* The song is split into multiple tracks that play during the battle against Photoshop Flowey, all beginning with "mus_f_," except for the music in the third and fifth stages.
** "Your Best Nightmare" begins with "mus_f_intro" and "mus_f_laugh" and then repeats "mus_f_part1" and "mus_f_part2" until the "mus_f_alarm" sound effect plays.
** Another part, "," is unused. However, its "end note" and alarm can be heard as mus_endnote and mus_f_alarm, respectively.
** In the third and fifth stages of the fight, "mus_repeat_1" and "mus_repeat_2" play before the alarm sound.
** Tracks for the six SOULs are named "mus_f_6s_1" through "mus_f_6s_6" in the game files. After ACTing during the SOUL phases, "mus_f_saved" plays.
* This is the fourth longest track in the Undertale Soundtrack after Bring It In, Guys!, Reunited, and Undertale.
* The drum loop in all parts of the song are heavily modifed versions of Amen Break, specifically "squash" (which plays during the Flowey segments) and "cw_amen14_175" (which plays during the SOUL segments.)
* The main parts using the "You Idiot" motif lack a clear tonal center, with the bassline being atonal and the melody being more obscure. The SOUL stages with the "Your Best Friend" motif are mostly modal, though the first is in plain E-flat major and the sixth and last is in D-sharp minor. Because of this, the track as a whole can be considered pantonal; not fixated on one tonal center and instead going through several arbitrary keys and modes, and sometimes atonal.
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zh:你最大的噩夢