Deltarune Chapter 4 All Piano Puzzles Guide

Deltarune is the spiritual successor to the indie hit Undertale, where players join in battles with their companions and solve the mysteries of the world. Piano puzzles make up some of the most memorable moments in Deltarune Chapter 4.

Some of these puzzles are easy enough to solve on your own, while others get a bit more complex. If you’re simply trying to continue the story, this guide covers every piano puzzle in Deltarune Chapter 4, including all solutions, optional rewards, and the requirements for unlocking the secret boss path.

Updated July 19, 2026, by Usama Ali: Deltarune’s early puzzles are pretty straightforward. Chapter 4 takes things up a notch by introducing more complex musical challenges. We’ve updated this guide with solutions for every piano puzzle in Chapter 4 of Deltarune, including optional block puzzles, moving piano challenges, and the Golden Piano sequence required to unlock the secret boss.

First Piano Puzzle

Image via GameRant | Sources: Toby Fox

The first piano puzzle in Chapter 4 acts as a tutorial and introduces the basic mechanics you’ll be using throughout the chapter.

You’ll run into this piano puzzle early on in the Dark Sanctuary. There are hidden buttons in the room which you can press to reveal the intended pattern. If you want to solve the puzzle immediately without searching for clues, simply enter the following sequence on the piano:

Successfully entering the notes opens the musical gate and you can continue through the chapter.

Second Piano Puzzle (Door to Old Man’s Study)

Image via GameRant | Sources: Toby Fox

The second puzzle appears after the party separates and the Old Man heads in a different direction. You can find the answers by interacting with the switches on the upper and lower left sides.

If you want to solve the puzzle immediately and skip the investigation, simply enter the following sequence on the piano:

The path ahead will open once the correct notes are entered.

Library Bookcase Puzzles (Blue & Green Pianos)

Chapter 4 introduces a new twist with Piano Block puzzles. Instead of simply opening doors, these puzzles move colored blocks throughout the room, allowing access to treasure and hidden areas.

First Piano Block Puzzle

Image via GameRant | Sources: Toby Fox

The first block puzzle can be found in the leftmost room above the Study.

Start by interacting with the blue piano. Enter this sequence:

Once completed, move to the green piano located on the upper side of the room and enter:

These movements create a route leading toward a ladder positioned beneath the blue block. Climb the ladder and search the nearby bookcase to claim the powerful AbsorbAx weapon.

Second Piano Block Puzzle

Image via GameRant | Sources: Toby Fox

After collecting the AbsorbAx, you can continue manipulating the green piano to find another secret reward. Interact with the green piano again and enter the following sequence:

The altered block positions create a new route into the leftmost doorway in the room. Inside, you’ll find a free MysticBand accessory.

Third Piano Block Puzzle

Image via GameRant | Sources: Toby Fox

The final block puzzle is required for story progression. Return to the blue piano and enter:

Up, Right, Down, Left, Up, Right, Up, Right, Up

Completing this pattern transports Kris into another hallway with multiple doors that eventually lead deeper into the chapter.

Pink & Green Piano Puzzle

The pink and green piano puzzle or the “Swap Piano” puzzle is one of the most complicated piano puzzles in Chapter 4. To get the solution, you need to collect two separate clue pieces hidden in the newly unlocked hallway.

First, travel all the way to the left side of the hallway. From there, go through the dark area while avoiding enemies until you find the first section of the piano pattern. Next, you need to interact with both the pink and green pianos.

• Start by selecting the pink piano and press Left
• Switch to the green piano and input: Left, Up, Right, Down
• Return to the pink piano and press: Down, Right

This arrangement lets you open a treasure chest that contains a ReviveMint.

After opening the chest, return to the puzzle and make the following adjustments.

• On the pink piano, press Up
• Then switch to the green piano and press Left, Up, Right

With the path restored, continue forward to get the second clue fragment.

Once both clue pieces have been collected, return to the central room and play:

The puzzle will solve immediately and you can proceed to the Jackenstein mini-boss.

Golden Piano Puzzle

To solve the Golden Piano puzzle, you will need to get three different music notes and assemble them together. Play the music correctly on the Golden Piano to solve the puzzle.

Before you start the puzzle, make sure you have the climbing ability. You can get the climbing ability by progressing through the story normally. After winning the fight with Jackenstein, he will give you Claimb Claws, which you can use to climb walls. Now, you’re all ready to find the music notes and piece them together.

Music Note 1 Location

Go to the old man’s study in the Dark World and start backtracking through the bottom left exit. You will reach a room with a stool near to the door. Go left again, and you’ll reach a room with spinning shadow creatures. At the end of the room, you’ll find a climbable wall. Climb it to reach an area with waterfalls. Dodge the waterfalls and climb further up. There, you can find a regular container of water, where you’ll encounter a mini-boss called the Water Cooler. Fight the boss, and he will give you the first music note.

Music Note 2 Location

Go back to the room with the stool beside its door. Go right, and you’ll eventually reach a corridor with glass windows. Go further right and you’ll reach a climbable wall. Travel upwards and everything will be dark around you. You’ll need to find a glowing figure in the bottom right corner. Interact with it and a path will open. Travel upwards along this path and step on the yellow switch to get your second music note.

Music Note 3 Location

Return to the old man’s study to find the last musical note. Go through the top left door, and you’ll find a dark door on the left. Go through it, and you’ll reach a room full of bookshelves. Go left, and you’ll eventually reach a room with a huge waterfall. Go behind the waterfall, and you will find a secret passageway behind it. The passageway will be dark, and you’ll need to find the glowing circle to open up the Wall of Bells.

Interact with the Wall of Bells and start climbing, which will bring you to another maze. Keep going right until you find a yellow switch. From there, stick to the right until you find a blue switch. Step on the blue switch to get the third and final set of music notes.

Go To The Golden Piano

After you have collected all three music notes, it’s time to find the Golden Piano and piece together the music. Go back to the old man’s study and go through the top left door. You’ll have to go through the dark door on the left again, but, this time, turn right after you enter through the door. You will notice a climbable bookshelf on the right side of the room. Climb upwards to reach the Golden Piano.

Play The Music Notes

Once you reach the Golden Piano, you’ll find a sequence of arrows that indicate how to play the notes. Simply follow the arrows and play the notes. After you complete the puzzle, the fireplace behind the old man’s desk will fall and a path will be revealed.

Rewards For Solving The Piano Puzzle

Solving the Golden Piano Puzzle opens the way to the secret boss, the Hammer of Justice. Head towards the new path behind the old man’s desk. Go right, and you’ll find the Justice Axe lying on the table.

Try To Get The Justice Axe

Susie will try to get the Justice Axe, which will cause the old man to appear and trigger a series of dialogues. The old man will ask you to pay for the Justice Axe and ask you to check the price tag. When you do, you’ll realize that you cannot pay the old man. Then, he will challenge you and offer you the Justice Axe once you win the fight. If you accept, the old man will transform into the Hammer of Justice and the fight will start.

Fight The Hammer Of Justice

If you manage to win the fight, you can get the Justice Axe and Shadow Crystal from the Hammer of Justice secret boss. The old man will say that he would have given you the Justice Axe and Shadow Crystal even if you lost. However, if you lose the fight, Susie refuses to take the items and asks for a rematch with the Hammer of Justice. So, you’ll need to fight again to get the items if you lose.

Large Organ Puzzle

Image via GameRant | Sources: Toby Fox

Near the top of the tower, players eventually find a large organ that has more keys than previous instruments. Fortunately, this puzzle is a lot simpler than it looks.

Interact with the organ once. After doing so, head to the right side and watch the cutscene featuring Susie and the Old Man. When you return, Kris automatically performs the required melody without any player input.

Moving Piano Puzzles

The Second Sanctuary introduces a completely different mechanic. Instead of moving blocks around the room, the piano itself becomes the object that moves.

First Moving Piano

To solve this puzzle and unlock the ladder, enter Down, Left, Up, Left, Down, Left, Up, Right

After completing the optional section, return to the piano and enter:

This second sequence lets you continue through the sanctuary.

Second Moving Piano

The last piano puzzle is in the Third Sanctuary. This sequence is much longer and timing becomes really important here.

To safely reach the end, enter:

Successfully performing the entire sequence brings you safely to the end of the area.

Released

October 31, 2018

ESRB

Teen / Language, Suggestive Themes, Mild Blood, Fantasy Violence

Developer(s)

Toby Fox

Publisher(s)

Toby Fox