Jul 09 2025
KANTAN Play: A Gadget Instrument That’s Easy to Use and Infinitely Versatile
This article was originally published on "fabcross", a Japanese web magazine focused on digital fabrication and hardware development. It is reposted here with permission. (The original article is no longer available online.)
By polymoog
Photo: Nao Miyamoto
Currently crowdfunding on Kibidango(Japan’s creative crowdfunding site), KANTAN Play is a handheld electronic instrument about the size of a classic Game Boy. Whether you're an engineer who loves music but never learned to play, or a musician who’s curious about gadgets but unsure about programming, KANTAN Play opens up a whole new world of creative possibilities.
KANTAN Play features an LCD screen and a grid of buttons reminiscent of a calculator or numeric keypad—all packed into a device the size of a classic Game Boy. Beside the display sit a spring-loaded jog dial and a rotary encoder, offering tactile control. With built-in stereo speakers and a headphone jack, it’s a fully self-contained instrument ready for instant play. But don’t be fooled by its small form factor—this little device holds big potential.
KANTAN Play: A New Instrument Born from InstaChord’s “Anyone Can Play” Philosophy
InstaChord made its debut in 2020, quickly gaining attention and achieving major crowdfunding success. It even led to the release of an entry-level model under the AIWA brand. This ukulele-sized electronic instrument lets complete beginners strum full chords simply by pressing buttons arranged to match the chord names shown on its screen. The same playing system is also available as a web app, KANTAN Play online, which allows users to try it out via taps on a smartphone or keystrokes on a computer.
Now, Yuichi Nagata—known as "Yuichi" and the creator behind InstaChord—is back with his latest project: KANTAN Play.
From left to right: KANTAN Play, the KANTAN Play online web app, and InstaChord.
Expanding the Reach of InstaChord’s “Anyone Can Play” Concept
Throughout the development and launch of InstaChord, Yuichi Nagata encountered a wide range of people. From the DIY communities at Maker Faire to international industry events like the NAMM Show in the U.S., he found himself engaging in conversations about technology and business with creators from around the world. At the same time, he met countless users and enthusiasts drawn to the idea behind InstaChord.
These interactions sparked a new realization.
Nagata:
“InstaChord was designed so anyone could play it, but I started thinking about people who still might find it difficult—like children or those with physical disabilities who can't easily use both hands. I wanted to create something even more accessible.”
It was around this time that Nagata connected with GOROman—a long-time InstaChord user and passionate advocate. Known for his evangelism of VR through work with Oculus and Facebook, GOROman had become a fan of InstaChord from its early days, eventually forming a strong friendship and creative partnership with Nagata.
By then, Nagata had secured international patents for his simplified chord-based music system using Roman numerals “I” through “VI”, branded as KANTAN Music. He envisioned licensing this system to toy companies and musical instrument manufacturers.
When he shared this idea with GOROman, the response was immediate: GOROman proposed creating a web-based version—and even took the lead in building it. The result was KANTAN Play online.
Unlike the guitar-style InstaChord, which typically requires two hands, the web app uses a drum pad-style interface that can be played with just one hand (though some chord types like m/M/7th may still require multi-finger taps). Nagata found this digital version brought a fresh kind of enjoyment.
It was also ideal for classroom use, making it easier to let more people experience playing music—and easier to explain to potential partners. Still, something felt missing.
Nagata:
“I realized I really wanted physical buttons. With real instruments, you don’t have to look down constantly. You rely on tactile feedback—and I think that’s essential for any musical instrument.”
The Encounter with M5Stack—and the Programmer Who Brought It to Life
Around that time, GOROman traveled to Shenzhen, where he had a chance to meet Jimmy Lai, founder of M5Stack(The company develops ESP32-based modular IoT platforms). Also present at the meeting were Masakazu Takasu of Switch Science—who is active in Shenzhen—and Lovyan, a Kyoto-based programmer from Switch Science with deep knowledge of M5Stack development.
M5Stack is a microcontroller module built around the ESP32 series and compatible with the Arduino IDE. Widely embraced by electronics hobbyists and makers, it's become a go-to platform for rapid IoT prototyping.
What sets M5Stack apart is its combination of a flexible programming environment, expansion ports, built-in LCD, sensors, physical casing, and I/O interfaces—all in a compact, easy-to-use package. Thanks to this integration and accessibility, it has become a central tool for DIYers and makers, particularly in Japan, over the past few years.
During the meeting in Shenzhen, GOROman pitched an idea to Jimmy Lai: what if they could turn an M5Stack into a musical instrument by docking it with a calculator-style interface?
Coincidentally, Lovyan had also brought along his personal InstaChord unit to show the team. As it happened, Jimmy Lai was a longtime music enthusiast himself—and the moment the idea clicked, things moved incredibly fast toward product development.
From right: Yuichi Nagata, CEO of InstaChord; Yuichiro Kuzuryu and Masakazu Takasu from Switch Science, who coordinated the development of KANTAN Play. On the screen is Rabiyan, also from Switch Science, who led the programming work.
Takasu:
“At first, when GOROman met with Jimmy, it seemed like adding a calculator-style interface to M5Stack would be a simple enough idea. Everyone was like, ‘Yeah, let’s do it.’ But once we heard Nagata-san’s deeper vision for the project, that’s when the real story started to unfold.”
Although the project kicked off without Nagata’s involvement at first, he welcomed the momentum once it became clear that a path toward commercialization was opening up. Still, it wasn’t going to be easy.
Nagata:
“Sure, we could’ve made a simple toy that plays chords at the press of a button and sold it at a low price. But once we chose M5Stack as the platform, the price point naturally went up. That meant we had to offer real functionality and appeal to match. I put a huge amount of effort into creating that ‘appeal.’ In the end, we built something that’s fun for everyone—from beginners to professional musicians.”
One of the key people who helped turn that vision into reality was Rabiyan. An expert in M5Stack development, his work is widely respected in maker communities around the world.
He also happens to be a devoted InstaChord fan. He was so fond of the instrument that he gave his personal unit to Jimmy Lai and later bought another one for himself.
Rabiyan:
“After joining Switch Science, this became the first product I got to work on from the very beginning of its development. I felt strongly about pouring everything I had into it.”
As the official distributor of M5Stack in Japan, Switch Science plays a central role in supporting the local M5Stack community. Executive director Yuichiro Kuzuryu also brought a deep understanding of electronic instrument development. During his time at Yamaha, he worked on early prototypes of NSX-1, the chip used in Gakken’s Pocket Miku, which brought Vocaloid (eVocaloid) technology into a hardware format.
With both engineering expertise and a background in creative electronics, Kuzuryu had this to say about Rabiyan:
Kuzuryu:
“Rabiyan not only understood the full potential of what M5Stack could do—he truly believed in it. And I think that’s exactly why we were able to achieve what we did.”
Rabiyan holding up his personal InstaChord. His open-source projects—Lovyan Launcher and Lovyan GFX—are widely praised for their speed, smooth rendering, and elegant graphics. These libraries showcase the full potential of M5Stack and its ESP32 chipset, making them highly regarded within the developer community.
Delivering a Truly Unique Playing Experience with KANTAN Play
Nagata:
“We met in August 2023 and quickly said, ‘Let’s build it and launch by the end of the year.’ The hardware side moved fast—but the software wasn’t ready yet. That’s when we brought in necobit, a creator known for their music-related DIY electronics. They helped shape what kind of MIDI and musical features we’d need for this to work as a real instrument.”
“Meanwhile, Rabiyan brought exceptional skills in UI performance and screen optimization on the ESP32. Beyond that, he contributed ideas from both a beginner musician’s perspective and as a gadget enthusiast. We used his sense of what would be genuinely fun as one of the guiding principles in development.”
One of the standout features that emerged was a programmable arpeggiator-like function. Following rhythm and arrangement presets—from rock to pop—you can play up to six instruments simultaneously, including guitar, drums, piano, and bass, all with a single finger.
By combining this with support tools developed for InstaChord—such as KANTAN chord notation—users can play full arrangements of existing songs using number-based chord charts. It’s a powerful and intuitive system that enables even non-musicians to create satisfying performances right away.
Nagata:
“I wanted to create something instruments typically can’t do. While the core idea—each button representing a chord—is the same as the web app, KANTAN Play goes further: you can perform six instruments, like drums or violins, not just simultaneously, but with optimized arrangements for each part. There are other instruments with auto-play, sure, but the ability to musically perform them all together—that’s a new experience.”
Why M5Stack? Expandability, Above All
KANTAN Play will be offered in two versions:
・The Full Set, which includes the M5Stack CoreS3 SE
・The KANTAN Play Base, a modular dock with buttons and ports
The Base is officially compatible with CoreS3, and CoreS3 SE. These models feature standard expansion interfaces like I2C, and support Bluetooth MIDI and USB MIDI. This means anyone can write open-source firmware to connect external sensors, buttons, and more via these ports—and tutorials may be available to help with such expansions.
Other models, like M5Stack Basic or possible future variants, won’t support the full KANTAN MUSIC instrument system out of the box. However, thanks to open-source firmware, the Base unit can still be repurposed as an M5Stack-compatible hardware expansion. With a bit of custom code, it could even connect to a wide variety of external devices—possibly for non-musical use as well.
At the heart of the KANTAN Play Base is a General MIDI sound chip SAM2695 from DREAM who is a French company providing DSP and tools, dedicated to audio processing. Because the ESP32 doesn't have to handle audio synthesis, there's zero performance overhead and no latency when playing sounds.
Of course, it’s not impossible to program your own audio engine on the M5Stack itself—but because KANTAN Play’s UI demands significant graphical resources, running both together would be quite advanced.
The Base unit includes built-in stereo speakers and a 3.5mm stereo jack, so you can play immediately without any additional gear—or plug in headphones or route the output to other audio equipment. It also features its own DAC and accelerometer, opening up creative controls like:
・Using MIDI CC(Control Change) signal to tweak effects
・Using the jog dial or two rotary encoders for pitch bends, chokes, or filter sweeps
Takasu:
“No one really decided it—it just felt obvious from the beginning: ‘Yeah, we’ll need some knobs.’ From there, it was Nagata-san who figured out how to make them matter.”
Nagata:
“Actually, Jimmy (M5Stack's founder) was the one who really pushed for the jog dial to have a spring. He wanted it to feel like bending a guitar string.” (laughs)
External MIDI connectivity is also supported through USB, BLE MIDI, and UART ports via Grove connectors. In addition to the I2C port on the M5Stack itself, the Base features two extra ports for UART and GPIO, allowing even greater hardware expansion.
These ports are being designed to be accessible directly from the KANTAN Play firmware, so users will be able to connect third-party MIDI interfaces, or even custom controllers—such as assistive pointing devices for users with disabilities. The team is putting a lot of care into accessibility, in line with Nagata’s original vision: an instrument truly anyone can play.
Nagata:
“You can send sounds created via programming or microphone sampling on the M5Stack directly to the DAC on the Base through I2C. The GM chip sounds are also routed through that same DAC, allowing us to mix them together and output as one. We’re designing the system so that any sound the M5Stack generates can be controlled through the KANTAN UI.”
“And since Rabiyan is a contributor to the official M5Stack libraries, this project sparked the idea of creating an official MIDI library for M5Stack. If that happens, it’ll make it much easier for others to sync their own sounds with the KANTAN Play interface.”
The yellow breakout box shown here is an interface connected to the Groove port, designed for external controllers using a 3.5mm jack. In addition to legacy MIDI interfaces, a variety of external connection options are planned—marking a clear evolution beyond the original InstaChord. Hardware developer necobit will be heavily involved in building these peripherals, and we can look forward to what comes next.
Merging with the Open Source Community: The Licensing Behind KANTAN Play
The development, manufacturing, and distribution of KANTAN Play is not handled by M5Stack itself, but rather by InstaChord Inc.. For InstaChord, the product also serves as a reference model to showcase what’s possible with the KANTAN Music system, which they aim to license more broadly in the future.
Nagata:
“Having KANTAN Play makes it much easier to demonstrate all the ways our system can be used. The numbered button layout (I to VI) that powers the KANTAN Music interface is a licensable application layer. That software only works when paired with the hardware—it won’t run on its own. The terms are clear: if you want to use the application, you need to use it with the official hardware.”
“On the other hand, the firmware for the hardware itself will be open-source. That means the Base could be repurposed entirely for other uses—say, as a game controller—without restrictions.”
So where does Switch Science come in?
Kuzuryu (Switch Science):
“We weren’t approached by InstaChord directly. We’re involved purely as the official distributor of M5Stack in Japan.”
Takasu (Switch Science):
“And as a distributor, our biggest goal is simple: we want to get more M5Stacks into more people’s hands.”
The KANTAN Play Base is more than just the user interface of the KANTAN Play instrument. Packed into its compact and stylish form factor are hardware features like physical buttons, rotary encoders, a General MIDI sound chip, a custom DAC, accelerometer, 3.5mm audio output, extra Grove ports, and a rechargeable battery. All of these components can be utilized as a versatile controller base for the M5Stack ecosystem. Since M5Stack is compatible with the Arduino development environment, users can easily integrate the device with existing open-source libraries, especially when paired with the firmware that will be publicly released.
Rooted in the Maker Movement
Editor:
You’ve gathered an impressive team of developers and collaborators around this project, building on what started with InstaChord. How do you reflect on the environment you're working in now?
Nagata:
“You won’t see Michinobu Uda, who co-developed InstaChord with me, in this story—though not because of a falling out! He was just tied up with another project this time (laughs). But being able to collaborate with top-tier talents like the folks at Switch Science is definitely one of the perks of being in a startup.”
“In big companies, you often have to do everything in-house. But in this kind of environment, we can pull together amazing people from anywhere in the world and take the fastest route to making something great. That freedom is what makes it fun—and makes great products possible.”
Editor: So why do you think such talented engineers and businesspeople are naturally drawn to your projects?
Nagata: “That’s a mystery even to me. Maybe it’s just because I seem like a nice guy who’s genuinely trying hard (laughs).”
When asked why talented collaborators seem to gravitate toward him, Nagata says with a smile, “Maybe it’s just because I seem like a nice guy who’s trying his best.” In the world of startups, technical skill is essential—but the personality and vision of the project’s leader can be just as important.
Takasu:
“Almost everyone involved in this project originally backed the InstaChord crowdfunding campaign (laughs). We’d all met through Maker Faire and similar communities, but even among DIYers, very few people actually take on projects that require moving real money from scratch. It’s hard. So having someone who can dream big and draw the bigger picture—that makes a huge difference.”
Nagata:
“People in the Maker scene have been incredibly supportive. There aren’t many examples of personal projects going through this kind of process, so I think they’re rooting for it and hoping it succeeds.”
Editor:
So from the perspective of those involved, it feels like they’re complementing your skills with their own—and you’re doing the same by reaching out to the Maker community. That synergy seems to create momentum.
Kuzuryu:
“At Switch Science, one of our core principles is to support our customers whenever they need help—and Nagata-san is a customer, so of course we’re all in (laughs). And let’s be honest: people like that are almost always doing something interesting (laughs).”
Takasu:
“Look at necobit’s work with MIDI, or Rabiyan’s programming—they’re both pros in their fields. But Nagata is doing something bigger that nobody else here could pull off.
I once asked Jimmy [Lai, founder of M5Stack] how often projects like this come along in a year, and he said almost never. Developers like us—we’re Makers. We’re always building something. Usually it’s for work or spun out of a hobby. But when a truly exciting opportunity comes along like this, everyone jumps in with enthusiasm (laughs).”
What’s Next for KANTAN Play and InstaChord: Aiming for Global Reach
Editor:
If the crowdfunding campaign succeeds, what’s the roadmap from now through the planned April 2025 shipment—and beyond?
Nagata:
“If we reach our crowdfunding goal, we’ll move into structural and PCB design while sourcing parts, aiming to ship by April. After that, I hope to bring it to music stores so people who missed the campaign can still get one. And I imagine users will come up with new ways to use it, which will help the product evolve even further.”
Editor:
How have your experiences with InstaChord influenced your approach this time?
Nagata:
“We’re still working toward launching InstaChord internationally, but rolling everything out at once would overwhelm our support system. So right now, we’re refining the firmware and manufacturing processes first.
The plan with KANTAN Play is similar—we want to perfect it here in Japan first, and then look toward the global market.”
InstaChord is one of the rare instruments designed, developed, and launched entirely from Japan—starting with a crowdfunding campaign and progressing to full-scale mass production. Nagata’s ambitious goal of “a musical instrument anyone can play” may sound idealistic—even unrealistic—but it’s exactly this bold vision, and his passionate drive to realize it, that inspires others to get involved.
We’ll be watching KANTAN Play and Nagata’s journey with great anticipation.