This is a page containing the many music tracks that are not present in Undertale or its soundtrack.

Sound Test

By traveling upwards from the "Box Road" intersection in Snowdin Forest, if the "fun value" in the undertale.ini file is set to 65, there is an additional 50% chance that a hidden "sound test" room will appear. The menu itself contains three very short looping tracks and a longer track that, once picked, cannot be deselected. None of these tracks are used anywhere else in the game.

Happy Town

A short, cheery jingle with the filename "mus_st_happytown".

Meat Factory

A short robotic track with the filename "mus_st_meatfactory".

Trouble Dingle

A short series of seemingly random robotic noises with the filename "mus_st_troubledingle".

Gaster's Theme

Upon selecting this track, no other songs can be selected. After listening to Gaster's Theme for a period, the room will cease playing music and display a screen that says "Thanks for your feedback! Be seeing you soon!". The protagonist is then returned to the room with the fishing pole. The file is titled "mus_st_him".



Hello. He-he-he-he-have some respect and don't spoil the game.
It's impossible to have mysteries nowadays,
because of nosy people like you.
Please keep all of this between us.
If you post it online, I won't make any more secrets.
No one will be impressed.
It will be your faaaaault.

The original "abc_123_a.ogg" file

This sound file contains seven text-to-speech voices from the FL Studio 11 synthesizer telling the listener not to post the game's secrets online. The odd filename was chosen to force it at the top of an alphabetical file listing and make its presence more obvious considering that all the other .ogg-format music and sound effect files present in the executable are prefixed with either "mus_" or "snd_".

As of Undertale v1.001, this sound file has simply been changed into laughter, presumably because numerous sources have already exploited the secrets of Undertale.


This track only plays in room_gaster, a room containing the 17th entry related to one of W. D. Gaster's experiments and only accessible through save file editing or debug mode. While it may not seem like there is much to it other than sounding distorted, it can be sped up by 1000% and have its pitch doubled to reveal Muffet's laugh, then reversed and looped.


This audio file was originally found in the Undertale Demo as "grandpasemi.ogg" and is reminiscent of the intro to "Metal Crusher". As of Undertale v1.001, this audio file has returned as "grandpatemi" in the form of a sound effect and plays when refusing to give Temmie the Temmie Flakes.

Grandpa Semi was a cut character that may have been planned to be the grandfather of Papyrus and Sans which stems from knowing that Semi refers to Semi Serif fonts. The Korean version of the Undertale Demo, which is based on an earlier build of the English Undertale Demo, also contains evidence suggesting that the phone call that the protagonist receives in Snowdin Forest from Alphys was planned to be used for Grandpa Semi instead. It is unknown if this character was cut for W. D. Gaster during development.


A regal-sounding variation of "Determination".


This song plays in an error room containing a dancing Annoying Dog. This error room can be accessed by modifying the SAVE file. The speed of the song varies.


This song plays in an error room containing a sleeping Annoying Dog. This error room can be accessed by modifying the SAVE file.


This song uses instruments from the SNES game, Star Fox. This is similar to Dogsong, which used instruments from a different SNES game called Mario Paint.


An unused third part of "Your Best Nightmare" which includes the alarm sound effect. This part of the track does not actually play and was scrapped in favor of reusing "mus_f_part1", "mus_f_part2", "mus_repeat_1" and "mus_repeat_2". This may be to make the fight shorter or maybe there were plans to include a fourth section to the Flowey boss fight, but only the song was implemented. Interestingly, in the OST version, "Your Best Nightmare" repeats the first part at the end.


An unused first part of "Finale". This track is never played, as "mus_f_finale_1_l" plays instead. It is simply a shorter version of the first part of Finale, most likely intended for when the player restarts their game after dying in the 2nd part of the Photoshop Flowey boss battle. "mus_f_finale_1_l" is most likely just "mus_f_finale_1" with the l standing for longer.


This song is simply "Good Night" in the Undertale Soundtrack and only plays during the ending screen of the Undertale Demo but not in the full version of Undertale.


This song is a slower version of "Ruins" with a variation on the melody.

Outside the game files

Alphys Lab (Unused)

An early version of Alphys's Lab that was left unfinished since it sounded too similar to a lab song from another game. It was replaced with "Alphys" in the final version.[1]

Undyne Battle (Unused)

An early version of Undyne's battle theme before her personality was fleshed out. It was replaced with "Spear of Justice" since it didn't feel like Undyne was "heroically punching [the listener] in the face."[2]

Dog Hole (Unused)

An unused track which was scrapped during development and was later uploaded to the official Tumblr.[3]

Dogtroid (Unused)

Allegedly, this track would have played upon beating the game fast enough. Once this happened, the Annoying Dog would appear in a bikini, which is a reference to the Metroid series.[4]

Undertale (Unused)

An unused iteration of "Undertale" which was said to be more melancholic and less effective. This iteration was scrapped when "Redline Day" from the anime film, Redline[5] inspired Toby Fox to change the chords and guitar accompaniment, which would then serve as the basis for "Memory".[6]


Patient was an unfinished song for Homestuck that used the "Doctor" leitmotif.[7] The song would later be reworked as "Another Medium" for Undertale.


  1. This is an early unfinished version of Alphys’ lab. It sounded too similar to a certain lab song from another game, so I scrapped it. While I think the new one fits Alphys more, the last part of this one is actually pretty cool. - undertale on Tumblr, September 13, 2016.
  2. I think this is the most finished-sounding of all the unused tracks. I made this before I really knew Undyne’s personality, so while the arrangement is good, I felt like it didn’t sound enough like being heroically punched in the face. - undertale on Tumblr, September 13, 2016.
  3. Dog Hole - undertale on Tumblr, September 13, 2016.
  4. Originally I was going to make it if you beat the game fast enough, you’d be able to see the annoying dog in a bikini. - undertale on Tumblr, September 13, 2016.
  5. @Phos_ That's actually correct. - Toby Fox (@tobyfox) on Twitter, September 13, 2016.
  6. Before the song “UNDERTALE” was completed, it went through a completely different iteration. This version sounds a bit more sad, which I think would have been less effective. It wasn’t until I heard a certain song that I was inspired to completely change the chords and guitar accompaniment. This new guitar accompaniment then served as the basis for “Memory,” so we have a lot to thank that inspiring song for. - undertale on Tumblr, September 13, 2016.
  7. not gonna use this for anything - fwugradiation on Tumblr, October 09, 2012.

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