MIDI-actuated restomod – An old, leaky player piano has been brought into the MIDI era in a largely reversible restomod. The builder kept the original pneumatic mechanism intact, added a MIDI-driven control system that maps to the same key paddles, and used an RP2040-based setup to dr
A player piano that once relied on punched paper rolls is now taking instructions from MIDI—without losing what makes it a player piano.
The maker behind the project describes the upgrade as a restomod, borrowing a term more common in the automotive world. The basic idea is familiar: take something old. add better technology. and end up with a machine that can do more. In this case. the “punched rolls of paper” are replaced by MIDI tracks—yet the piano’s underlying mechanism stays where it belongs.
Unlike many conversions that permanently change a machine’s guts, this one is designed to be mostly reversible. The builder did “drill few holes and slots in the original wood. ” but those changes aren’t said to alter the integrity or the original operation of the player piano mechanism. The MIDI-controlled solenoids simply poke the same key paddles from below that the pneumatic system used. To the listener or operator. the piano behaves the same—unless the doors that reveal the music scroll are open or the piano is playing with MIDI rather than rolls. The big difference is what the piano can access: instead of a “paltry selection of hard-to-find piano rolls. ” it can play the “whole wide array of tracks” that exist in MIDI form.
The electronics are where the project gets ambitious. Each of the relays is driven by a MOSFET through shift registers to produce 88 outputs from a single Pi Pico. A level shifter is involved to let the RP2040 handle 5 V logic while the system communicates correctly. For volume control, the builder isn’t planning to slam every note at full force. The RP2040’s PIO is used to create a PWM-style signal to “soften the solenoid blows” when needed.
Power management matters too. The setup staggers the pulses so that multiple relays aren’t pulsed at the same time when a MIDI file calls for chords. That approach reduces the load on the power supply and helps keep the playback from becoming a single, simultaneous electrical event.
The project also leans into an unexpected overlap between the old and the new: the presentation of an Apple ][ being used to create the piano rolls. The builder points to how more than one era can share the same music-making pipeline—even when the medium changes.
The full walkthrough is shared in a YouTube video embedded with the project details: https://www.youtube.com/watch?v=elFVeop7Cws.
player piano MIDI restomod RP2040 Pi Pico MOSFET shift registers relays solenoids PWM MIDI tracks Apple ][
So it’s basically a regular player piano… but with an Arduino? Cool either way.
I don’t trust it. “Mostly reversible” sounds like a PR line lol. If they drilled holes in an old instrument it’s still not the same.
Wait, they’re using an Apple ][ to make the rolls? So like… Apple is controlling the piano directly? That part confused me. Also MIDI chords pulsing power at the same time? Sounds like it could blow fuses unless they really engineered it.
Honestly I’m just stuck on “leaky player piano” like does it leak air the whole time and that’s why the notes are janky? If it can play “the whole wide array” then why didn’t anyone do this sooner. Kinda makes the paper roll thing seem pointless but I guess that’s nostalgia.