There are plenty of unconventional methods to make music, like Shawn Wasabi’s MIDI controller, which is fashioned with 64 arcade buttons, or the cute, squawking Otamatone, which YouTubers have mastered to cover a wide range of beloved tunes. Now, novelty Chinese calculators might be the latest instrument of choice for burgeoning bedroom musicians, particularly the delightful Japanese YouTuber who goes by It’s a Small World. Watch as the mysterious musician absolutely nails the Super Mario theme song on a symphony of four calculators.

Though they look like the average calculator that your dad has stashed away in the “everything” drawer, they’re so much more. The musical calculators used here are the AR-7778 and AR-8001, available on Amazon Japan for about $22, or Chinese retailer Taobao for about $5. They’re made by a Chinese calculator manufacturer called Jia Ling Tong, which makes a few other musical models. Here’s another YouTuber, A Yuu, playing the vocaloid Hatsune Miku’s hit single “Senbonzakura” on the AR-3058.

The calculators all use two AAA batteries and are preprogrammed to play around 20 songs. The songs aren’t just short little ditties either; they’re extensively long, playing the entirety of classics like “Für Elise.” All the calculators feature different modes. You can set it up to have a woman recite the numbers back to you in Chinese, or you can get to the good stuff and use it as an instrument, with each button corresponding to a musical note. Playing in this mode will leave the screen permanently displaying “2005-01-01,” which I assume is the year it was manufactured.

It’s a Small World kindly takes us through a tutorial / behind-the-scenes look at how they practice playing on the calculators. There’s a funny bit at 6:15 when they have to “tune” the calculators; replacing the batteries sometimes changes the timbre of the notes, which is a testament to just how old and wonky these calculators are. Yet, they’re still playable with enough patience and dedication.

With two calculators, there’s the classic piano-playing method of having the left hand play the bass lines on one calculator, and the right hand play the melodies on the other. I do not know how the four-calculator setup works, and will assume it’s just some sort of sorcery. I have no trouble believing that It’s a Small World is some sort of superhuman wizard, because they also play hits like “Despacito” and “Shape of You” with perfect musicianship. Further exploration of their channel turns up unexplained oddities like “All Star but it’s singing water,” which is just 54 seconds of them slapping the water. I’m intrigued, and now also a proud subscriber.

And, of course, the calculators also have a silent mode where you can just use the calculator as god intended. But now that you know what’s possible, what’s the fun in that?