By Rúnar Berg

Play the theremin with random strangers on the internet.

How do I use this? To play simply point your mouse to a desired location on the rainbowed canvas, press the mouse button and hold it. Release the button again to silence the theremin.

If you’re lucky enough to be playing on a touch screen display, it is enough for you to touch the canvas where you want to play it. Note that you can play multiple notes at the same time by using more than one finger.

The vertical axis represents volume (up means louder) and the horizontal axis represents pitch (right means higher). So to play a loud base, click the upper left corner. And to play a soft high tone, press and hold somewhere above the bottom right corner.

What are the strings in front of the rainbow? The strings in front of the rainbow are sort of like notes on a piano. You don’t have to to use them if you don’t want to. But if you do, a black note on a piano is represented here as a repeated color. With C and C♯ as yellow, D and D♯ as green, E as blue, etc. And if you really want to know, the left edge is tuned at A2 = 110 Hz, and the right edge is tuned at A6 = 1760 Hz.

What are jam sessions? If a session is to noisy for you, you can create a new channel simply by entering a new path in the address-bar of your browser, e.g. /my-new-channel, your new session will then be listed under jam sessions for others to join. If you want a private session start your new channel with an underscore, e.g. /_my-secret-channel, and you’re channel won’t be listed under jam sessions.

How did you make this? This app uses the Web audio and Web sockets technology to connect your theremin session with everyone else’s. The backend is written in Rust using WS-RS, to handle the web socket connections, and Hyper, for HTTP connections. This app is MIT licenced and you can read (and fork) the source code on GitHub.

Lev Sergeyevich Termen playing his invention. He used his hands to play, you can use a computer mouse or touch your screen with your finger or a pen instead. Picture is public domain via Wikimedia Commons.