Musical Hacks

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ESP32 Music Sequencer Is Clearly Nailing The Y2K Aesthetic

August 15, 2026 by No comments

Do you remember back when electronics came in clear cases? Back around the turn of the millennium, when translucency was chic. [3DSage] sure does, which is why he went to great lengths to make a clear case for his Clear Retro Music Sequencer.

The sequencer itself is based around an ESP32-S3 module with a built-in display, and a rotary encoder that handles most of the input. Most, because there’s a second button and a stylophone-like array of brass rods on one edge of the custom PCB he made with his fiber laser that can also handle note input. Other notable features include a phono jack with built-in switching so the tunes come out automatically from headphones or the internal speaker, and a AAA battery-lookalike. It’s a small detail, but that 666 mWh 3.7 V lithium cell is the demon’s meow for this project, seeing as it gives the convenience of a modern battery without compromising that Y2K look — remember you can see the battery through the translucent case.

About that translucent case: it’s 3D printed out of PETG, with settings similar to those we’ve reported on before: hot, slow, and don’t cross the streams! Which is to say every layer must line up with the one above. Oh, use filament fresh out of the drier of you live somewhere as humid as [3DSage]. The result is not totally see-through, but an application of clear enamel fills in the surface well enough to read through, giving the vintage look [3DSage] was after. To complete that Y2K feel, he turns the device into a slap bracelet, because why not? For those of you who missed due to the aforementioned federal prison arc, slap-on wristbands were all the rage amongst the kids back in those days.

The wristband is a length of measuring tape at its core, the springy steel having been cold-worked to hold the radius of [3DSage]’s wrist in its relaxed state, encapsulated in clear gorilla tape for comfort. We probably don’t have to tell you that getting slapped with a raw tape measure isn’t the nicest. For the actual operation of the sequencer, check out the video embedded below — the first 9 minutes cover the build, while the rest shows off the product.

Of course you don’t need an ESP32 for this kind of music maker– you can do it with a C64, or even discrete parts and rope-core memory. 

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A guitar stands magically on it's end in the foreground of a snowy sunrise. A large 3D-printed robot is attached to the fretboard, and a smaller robot sits over the sound hole.

Twin Guitar-Playing Robots Will Work For Tab

August 14, 2026 by 9 Comments

Remember Animusic? They were these incredible animated music videos with original tunes being played by computer-generated robots. Well, the MegCell Pulse might be the coolest robots-playing-music thing we’ve seen since Animusic.

Built by [Bruce] over six years’ time, this futuristic wonder features two robots working in concert to play acoustic guitar, just like a pair of human hands would. You just feed them digital tablature, and off go the fraternal twins, with one doing the fretting, and the other doing the plucking via six individual plectrum. It’s digital music producing analog sound from a physical instrument.

How does MegCell Pulse work? It’s essentially a system of gears, magnetic actuators, and arms, contained in a 3D-printed structure. The only real limitations are that it can’t traverse the entire fretboard, nor can it slide between frets. That said, you can absolutely buy one for your own guitar via [Bruce]’s modestly-goaled Kickstarter.

The kicker here is that you can’t buy an assembled MegCell Pulse; you must print and build it yourself. Back on the upside, the most expensive supporting tier is a mere $100. For that price, you get the complete digital plans. That includes 3D print files, an assembly guide, the control software, and a parts list. Be sure to check out the demo videos embedded after the break.

We have certainly seen robots playing guitars before, although admittedly, it’s been a minute.

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Only The Hottest Tunes Play On This Fire Organ

August 6, 2026 by 19 Comments

Most musical organs use air as their working fluid, but there’s nothing in the rule book that says they have to. Calliopes have used steam for 150 years now, while [Look Mum No Computer] has opted to go full pyromaniac and pump propane though the summer’s hottest new instrument.

Just like every steam or compressed-air organ we’ve heard, the tuning could use some work — though we have faith [LMNK] will get to that in due time — and just like the circus organs of yore, it sits upon a trailer for easy transport. That may or may not be to flee from fire marshals, because the whole point of the propane organ isn’t to waste flammable gas: it’s to burn it. The fire itself doesn’t make a sound; that’s the propane going through the copper organ pipes. Igniting it is just bonus, and what a bonus it is!

Said ignition is provided by regular spark plugs and ignition coils, like you’d find in any internal combustion engine. An earlier version used pilot lights, but those had an annoying habit of blowing out and were wasteful of propane to boot. This way the same MIDI signal that controls the gas valve can set the ignition off, and provide a light show to go with the sound. The video embedded below deals with building this new ignition setup, but he has other videos on the channel detailing other aspects of the construction. If you’re not so interested in that and just want a performance, jump right to 16:47 for the obligatory Toccata and Fugue.

Perhaps [LMNK] will write a theme tune for his museum of obsolete technology on this organ, with accompaniment from his rope-core drum machine, and effects on his tape delay synth.

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Circuit Bending, But Make It MIDI

August 3, 2026 by 2 Comments

Circuit bending is a chaotic art. At its simplest, it can just involve making connections between random points on a circuit board to create weird sounds in musical hardware. Or, you can complicate things, get really specific with your hookups, and twist them with various sorts of modulation. [Simon the Magpie] has been working on something closer to the latter category, with his neat project to add MIDI to the circuit bending world. 

The concept is straightforward enough. [Simon] has created a device that you place in line with your circuit bent connections, particularly those that create pitch bends with pots thanks to their variable resistance. You can then play your MIDI keyboard, and the device will vary the resistance in the circuit and bend the pitch at your command. [Simon] simply calls the device MIDI TO RESISTANCE, because that’s… precisely what it does, with the aid of a digital potentiometer. He then demonstrates it doing its thing on pitchbent toys, and it sounds pretty radical in use.

If you’re trying to make your circuit bent toys and instruments more musical, this build should serve as a great inspiration. We’ve featured other oddball musical hacks in a similarly creative vein before, too—such as using mixers as a synthesizer in their own right. Have fun out there.

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Easy Theremin Uses ESP32

August 2, 2026 by 6 Comments

The Theremin is that classic electronic musical instrument that makes those weeee-ohhhhh noises which were so popular in mid-century science fiction movies. Mid-last-century, that is, because this century is just beginning. In any case, you could build one with old-school analog electronics, or you could go a more modern route, as [ericCycles] did.

The build relies almost entirely on an ESP32 microcontroller with minimal supporting circuitry. Like any other Theremin, pitch and volume are controlled by moving hands closer or farther away from two antenna. In this case, the ESP32 uses its capacitive touch circuitry to detect effectively detect hand proximity to the two antenna in question, and uses those values to control the pitch and volume of a synthesized waveform. That waveform is then pumped out over the onboard digital-to-analog converter for playback on external speakers.

If you want to build a simple Theremin-like instrument quickly and easily, it’s hard to beat the simplicity on offer here. We’ve featured some other fun variants over the years, too, like this version that uses time-of-flight sensors for the human interface.

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A Music Box With A Very Modern Heart

July 27, 2026 by 3 Comments

A ballerina music box is a charming ornament, but it remains one that is limited by its mechanism to a very short performance. [ShielaDixon] has one, and decided to make so much more with it.

The music box mechanism is a simple clockwork motor with a comb that’s picked by a drum to make the notes. Her box retains the mechanism to give the ballerina her performance, but replaces the comb with a microcontroller and audio channel. This is no mere MP3 player though, instead it’s a music box in itself. Each note of the comb was sampled, and the board plays them just as the music box would, under instruction from a text file containing the music. The repertoire can now go on for far longer, and contain many more compositions.

We like this hack, for its effectiveness, and for its recreation of the music box rather than simply playing a recording. Meanwhile if you recognise [ShieldDixon] from these pages, we’ve in the past featured another musical project of hers, a MIDI recorder.

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A Feature-Rich Drum Machine

July 20, 2026 by 6 Comments

A little over a month ago, we featured a project from [Igor] who built 64 bits of DRAM from scratch using discrete components. Jokes about memory pricing aside, he did have a use case for such a small amount of memory — he is using it in a custom-built drum machine. But featuring the memory build and not the drum machine was perhaps putting the cart before the horse, so in this video, [Igor] shows off the construction of each part of his impressive 16- or 64-step sequence drum machine.

This isn’t Igor’s first drum machine, either, although his previous build was a bit more limited. It had fewer steps in the sequence and didn’t quite have the range of his newer model. The upgraded version can play more steps but also includes force-sensitive drum pads based on piezo sensors and more voices (drums) as well. Each voice is built electronically using various op-amps and passive components, and [Igor] has the schematics for each of them, as well as every other part of the drum machine, for those looking to recreate any part of this on their own. There’s a lot going on in this lengthy video as well, so for the musically inclined, it’s worth taking a look in full.

Now that our horse is in the correct position in front of the cart, it’s worth going back and looking at the memory build if you missed it when it first ran. A small amount of memory makes the machine programmable rather than just playable, and truly expands the capabilities of a machine like this in the recording studio.

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