Mouse P.I. for Hire Piano Guide: Hitting the Right Notes
Before you smash your keyboard in frustration trying to play Beethoven, I have the exact sequences you need to solve every musical roadblock in the game.
Being a private investigator usually involves kicking down doors and firing off rounds. If you want to know which loadouts actually clear those rooms efficiently, you should take a look at my Mouse P.I. for Hire Best Weapons Ranked list. Occasionally, the game forces you to put the guns away and flex your brain. There are two highly specific piano puzzles hidden in the campaign. They completely halt your progress toward a perfect completion file if you ignore them. They are tucked away in optional areas, and the clues are incredibly easy to overlook if you are rushing through the levels. I am going to walk you through exactly where to find these instruments and what keys to press so you can extract your rewards.
The Mechanics of the Music
These puzzles are not designed to test your actual musical talent. They are strict observation tests.
If you stumble into a room with a piano, do not start randomly hitting notes. The game does not reward guesswork. The correct sequence is always written down on a physical clue hidden somewhere in that exact same area. Instead of running in circles looking for a tiny scrap of paper, you can use the cheat sheet below to bypass the detective work entirely.
Surviving the Curdsville Nuthouse
Your first musical hurdle happens during the One Flew mission. This specific location is a maze of hostile enemies, so you need to clear the area before you sit down to play a tune.
Unlocking the Path to Gloria
Push through the mission objectives until you finally obtain the Jar-Head weapon. Once you have that locked into your arsenal, pull out your Detective's Brush and follow the glowing trail. Keep moving forward until you run directly into an NPC named Millie. From her location, you will see a bridge directly ahead of you. Cross that bridge and immediately look to your left to spot the piano sitting against the wall.
Walk up to the keys and play the sequence C-A-G-E. You will hear a mechanical grinding noise as a secondary bridge lowers nearby. This newly opened path leads you straight to Gloria. You must snap a photo of this NPC to clear your active bounty. If you are struggling to track down the rest of the secondary objectives in this area, reference my Mouse P.I. for Hire Side Jobs Guide to ensure you do not miss a single payout.
Investigating the Quagmire
The second piano is located deep inside the Swamp Oddity mission. The atmosphere here is heavily distorted, making it very easy to walk right past the building you actually need to enter.
Securing the Baseball Card
You are looking for the Strange Cabin. Fight your way inside and locate the dedicated music room. The piano is sitting in plain sight.
Walk up to the instrument and play the sequence A-C-E-G. The second you hit that final G note, turn around. The closet door directly behind you will pop open, revealing a hidden room. Step inside to claim your Baseball Card.
Securing this specific card is a hard requirement if you want to achieve a 100% completion rating on your save file. The game does offer a small safety net if you somehow forget to play the piano. You can technically purchase this exact Baseball Card later from the Soup to Nuts vendor or at a Roadhouse. I strongly advise against doing that. Your cash is highly limited in this game, and spending hard-earned currency on something you can get for free is a terrible business decision. For a complete breakdown of where to find the rest of the free hidden items, check out my Mouse P.I. for Hire All Collectibles Locations Guide and keep your wallet full.
