Sound Workshop is a one-person instrument workshop run by a designer named Chris. His new work, the Flexur T2, is a standalone synthesizer inspired by the Trautonium — a mostly forgotten 1930s German electronic instrument. There are no piano keys. Instead, two floating touch bars: slide your finger horizontally to control pitch continuously across any range, and press down to control volume and filter simultaneously. The same finger, the same gesture, governs both where you are and how hard you're playing. In June 2026 Chris opened a crowdfunding preorder; 135 units sold out in five days, raising over $186,000.

The Trautonium was invented in early 1930s Berlin by Friedrich Trautwein and Oskar Sala. It used a metal wire pressed against a resistance rail — pitch was continuous, and you could glide to any position between notes. Sala used it for forty years in relative isolation, creating among other things the disturbing bird sounds for Hitchcock's The Birds and a vast catalog of works almost no one heard. He died in 2002, and the instrument's living tradition very nearly ended with him. Chris rediscovered the touch bar principle in a video and recognized something he had been looking for: an interface that could both jump between notes and glide between them, the way a singer does without thinking about it.

In SAE aesthetics, the piano keyboard is a completed chisel-construct. Over three centuries it carved pitch into a discrete grid: each note is a fixed point, jumping from C to D means skipping everything in between. Analog synthesizers inherited this architecture, MIDI encoded it into digital protocol, DAWs painted it into the timeline — the entire edifice of modern music technology rests on the keyboard's grid. MPE (MIDI Polyphonic Expression) is the latest extension of this construct: it adds per-note pitch bend and pressure to each key, but it starts from the same premise — one key = one fixed pitch. Expressivity is a patch layered onto the grid, not a replacement of the grid itself. Flexur's chisel is the touch bar: it doesn't add a patch to the grid, it replaces the grid's starting point. Where the keyboard begins with fixed pitches and bends outward, the touch bar begins with continuous space and arrives at stable notes only when you stop moving. Gliding is the default; landing is the intention.

The remainder is in the path between the notes — the space from C to D that the keyboard's grid chiseled away. Singers never jump directly from one pitch to another; they glide toward it, bend inside it, vibrate on it. String players do the same: the trace between positions is part of the music, not an error. The Trautonium put this path back at the center of the playing surface, not as ornamentation but as the starting condition. That is the first remainder: the continuous pitch space between notes, which never physically disappeared, only got declared unplayable by the keyboard's structure and apologetically handled by a small pitch-bend wheel. The second remainder is the coupling of pitch and dynamics in the same physical gesture. On a piano or synthesizer, key velocity gives you attack loudness and then the note's volume disconnects from your finger; after the attack, pressing harder does nothing. On a touch bar, the pressure remains live throughout the note — pitch and dynamics are always coupled, as they are in the human voice, where singing louder changes not just volume but tone and weight. The keyboard separated these two things. Flexur binds them back together.

The reason to pay attention now is that MPE is becoming the new construct for expressive synthesis. The Haken Continuum, ROLI Seaboard, LinnStrument — all of them operate within the MPE framework, extending keyboard logic rather than replacing it. Once "expressive synthesis = extended keyboard + MPE" solidifies into a name, the more radical alternative — the touch bar, the Trautonium principle, continuous pitch as the origin rather than an extension — will be absorbed as a historical footnote. Flexur appears before that naming completes. Chris writes: "Our mission is to make an instrument that allows me to play the vocal melodies from my favorite songs." That is a mission about reclaiming remainder: taking back what the keyboard took and called unnecessary. The Trautonium was invented in 1930 and was never absorbed into any category by the synthesizer industry. Flexur appears in 2026 and proves the logic is still alive. The path between the keys was never truly gone.

Han Qin (秦汉) · @hqinjarsy · SAE Judgment & Aesthetics