There are a lot of pianos in Deltarune Chapter 4, from small-time puzzle pianos to a grand golden organ required to access the chapter's secret boss. While you have to track down the correct note combinations for each of these pianos to progress through the main story of Deltarune Chapter 4, you can actually play some classic Undertale songs to get some unique dialog from Ralsei and Susie.

You can only play these songs at a specific piano in Deltarune Chapter 4. It's the big blue organ that opens the way to the Dark Fountain in the Old Man's study. You can play any combination of notes on this instrument, and there's even a button to shift the octave so you can create a wider range of melodies. There are quite a few easter egg songs you can play on this piano, and each one gets a great reaction from the party.

Deltarune Chapter 4 Walkthrough Header
Deltarune Chapter 4: 100% Walkthrough

Deltarune Chapter 4 is one of the more lore heavy parts of the game, and there are a ton of secrets to discover in between the main story beats.

1
By 

Deltarune Chapter 4 Piano Easter Egg Songs

Deltarune Chapter 4 Piano Music

In addition to the sheet music required to continue, these are all the secret songs you can play on the piano in Deltarune Chapter 4.

The table below uses compass notation, so the directions match the in-game arrows. Octave shifts are denoted with a $ before the note.

Song

Notes

His Theme

$SW-E-O-$SW-$NW-$NW-O-$SW-O-$SW-$NW-$NW-O

Your Best Friend

SE-SE-S-SW-SE-S-S-SW-E-$SW

Annoying Dog

O-S-SW-W-S-S-SE-S-E-O-S-SW-S-SE-S-S

The Legend

$W-O-SE-N-NW-SW-E-SE

Don't Forget

SE-S-SW-SW-SW-SW-SW-O-SE-E-E-E-E-E-SE-E-O-O-O-O-O-NW-N-NW-SW-SE

Lost Girl

$S-$W-$N-SE-NW-N-SW-SE-W-$NW-$N-SW-$NW-$N

Spear of Justice

SW-S-E-SE-O-E

Rouxls Kaard

SE-O-$NW-$W-$W-W-SW-S-SE-E-O-E-SE

Heartache

$W-$N-$NW-$N-$W-$W-$NW-$N-SW-SE

Dark Sanctuary

$W-O-SW-E-O-E-O-E-SW-E-O-E

Megalovania

$W-$W-W-SE

You've Got a Friend in Me

SE-SW-SE-W-SW-O-W-N-W-N-SW

Chopsticks

S-S-S-S-S-S-S-S-SE-SE-SE-SE-SE-SE-SE-SE-NW-NW-NW-NW-NW-W-NW-N-N-N-N-NW-W

Heart and Soul

$N-$N-$N-$N-$NW-$W-$NW-$N-E-SE-SE-SE-SE-E-O-E-SE-S

Once Upon a Time

$SW-SW-E-O-SW-$SW

Most of these just result in little dialogue quips from either Susie or Ralsei, but you really should try playing Megalovania at least once. There's a special interaction for it. You won't get any items or equipment for playing these songs, though, so feel free to move on once you've had your fill.

There are plenty more secrets to discover in Deltarune Chapter 4, and even though it may seem like you're nearing the end of the chapter by the time you reach the big piano, there's still a lot of stuff to do before the credits finally roll. Before moving onto the Dark Fountain, you should also take the time to fight Chapter 4's secret boss if you're up for a challenge.

Rating block community and brand ratings Image
Deltarune Tag Page Cover Art

Deltarune
Display card tags widget
RPG
Display card system widget
Systems
PlayStation-1 super greyscale 8-bit logo PC-1
Display card community and brand rating widget Display card open critics widget
Top Critic Avg: 86 /100 Critics Rec: 83%
Display card main info widget
Released
October 31, 2018
ESRB
Teen // Language, Suggestive Themes, Mild Blood, Fantasy Violence
Developer(s)
Toby Fox
Publisher(s)
Toby Fox
Engine
gamemaker
Prequel(s)
Undertale
Number of Players
Single-player
Display card main info widget end Display card media widget start Display card media widget end

WHERE TO PLAY

DIGITAL
Checkbox: control the expandable behavior of the extra info

Steam Deck Compatibility
Unknown
PC Release Date
October 31, 2018
PS5 Release Date
June 5, 2025
Nintendo Switch Release Date
February 28, 2019
Nintendo Switch 2 Release Date
June 5, 2025
Genre(s)
RPG