The Trautonium is the great dead end of electronic music. Invented in the 1930s in Germany by Friedrich Trautwein and developed for decades by Oskar Sala, it replaced the keyboard with floating bars: slide your finger for pitch, press for loudness. It could jump between notes like a keyboard or bend between them like a cello, which is to say it could do what a human voice does. Then it went nowhere. Sala never trained successors, the instrument never went into real production, and its most famous work, the shrieking bird sounds in Hitchcock's The Birds, outlived any memory of what made them.
Flexur, from the small builder Sound Workshop, is the first serious attempt in decades to put that interface back into production. Two floating touch bars for continuous pitch and pressure, paired with a deliberately simple subtractive synth underneath. The builder's own description is the best one-liner in synth marketing this year: "a Cello crossed with a MiniMoog in the spice mines of Arrakis."
Watch the prototype in action before reading another word; the bars make more sense heard than described:
The design argument is specific and correct. Sound Workshop's stated mission is an instrument that can play vocal melodies, and singers do something most electronic instruments can't: they constantly switch between discrete jumps and smooth slides, often inside a single phrase. Keyboards only jump. Ribbon controllers and the Ondes Martenot mostly slide. The Trautonium bar does both with one finger, and because that same finger controls loudness through pressure, the expression is unified the way it is on an acoustic instrument. Your other hand stays free for the knobs or lands on the bar for polyphony.
The team walks through the Trautonium's history and how they prototyped their version here:
The synth under the bars is the second good decision. Expressive controllers usually arrive tethered to editor software with hundreds of parameters. Flexur goes knob-per-function, Minimoog style: every control on the surface, nothing behind a menu. There's still depth, a 6x12 mod matrix with dedicated intensity sliders, preset and mono/poly/arp modes, but the instrument reads at a glance.
It's also a controller in its own right. Four parallel CV outputs (pitch, gate, envelope, force) for driving Eurorack or analog monosynths, MPE MIDI over USB-C and TRS for expressive digital synths, and a full-size balanced quarter-inch jack so it plugs into an amp or mixer like a guitar. That last detail says a lot about who this is for: people who intend to leave the house with it.
This is a crowdfunded preorder, and Sound Workshop is unusually plainspoken about what that means. The presale price was $1,399 against a planned $1,599; the $75,000 goal was hit in two days, and all 135 units sold out in five, with $186,000 raised as of late June. Shipping is quoted at 6 to 24 months, and the wide window is a deliberate attempt to set expectations rather than optimism. The first hundred units are being built in-house to keep iteration fast. The named engineering risk is the custom capacitive multi-touch sensor, with a resistive fallback if it fails.
Two things separate this from the average hardware campaign. First, a track record: this team has already shipped 35 units of its Quord instrument and 550 LinnStrument surfaces for Roger Linn's expressive controller, so building and shipping electronics is not new to them. Their earlier Wiggler experiment is part of the same lineage, each instrument a different answer to the same question about pitch expression. Second, the refund policy, which is the genre's best: every preorder is a reservation, fully refundable any time before your unit ships, no restocking fee, and if the project dies for any reason, everyone gets their money back.
The current run is gone, but the waitlist is open on the product page, and the team posts build progress on Instagram and YouTube. If the Trautonium finally gets its second life ninety years late, this is what it will have looked like: a small shop, a hundred units at a time, and an interface that was right all along.
