I still use the original Arturia KeyStep 37 because 37 slim keys are the right desk-sized musical range for me and its arpeggiator, sequencer, chord tools, MIDI, sync, and CV connections make it useful without a computer. The newer KeyStep 37 mk2 is the better new purchase for deeper sequencing and modern connectivity; it does not make the original stop being the controller I already like.
Why 37 keys is my desk format
I have gone through several 37-key MIDI controllers. The format is wide enough to play with both hands, establish voicings, and move across a few octaves without constant button presses, but small enough to remain directly in front of a computer and other hardware. Twenty-five keys feels like note entry to me; a full-size board turns the desk into a keyboard stand.
The original KeyStep 37 has a velocity- and aftertouch-sensitive slim-key keybed that feels good to me. Four knobs and a display expose chord and MIDI control functions without filling the surface with a complete DAW mixer. I use it as a controller, but the reason it stays is that it also has a real polyphonic sequencer and arpeggiator.
MIDI DIN, USB MIDI, analog sync, and pitch, gate, and modulation CV make it a useful translator among software, MIDI hardware, and modular or semi-modular gear. It can begin an idea without the computer being the clock and finish as a normal USB controller when the computer is the center.
Original KeyStep 37 vs KeyStep 37 mk2
| Controller | Best at | Upgrade question |
|---|---|---|
| Original KeyStep 37 | Immediate 37-key control, sequencing, arpeggiation, chords, MIDI, sync, and CV | Already solves my workflow; older USB connection and a simpler pattern system |
| KeyStep 37 mk2 | A current USB-C design with expanded patterns, OLED feedback, generative tools, and deeper connectivity | The stronger new purchase, but an upgrade only if those additions change the music |
| Basic 37-key USB controller | Playing software instruments at the lowest complexity and cost | Usually gives up the standalone sequencer, clock, DIN MIDI, or CV role |
The mk2 can hold many more patterns and adds an OLED screen, USB-C, mutation and generative options, and expanded performance control. Those are real improvements. My point is not that the older model is secretly newer; it is that a controller can remain complete for a particular setup after the market advances.
The best controller is the one that starts music
I keep the KeyStep within reach of the Teenage Engineering OB–4. Together they lower the activation energy between an idea and audible notes. The KeyStep can run a sequence or drive an instrument; the speaker makes playback immediate. Neither requires me to reconstruct the studio before I can hear whether an idea has life.
If I were buying today, I would compare the original's used price against the mk2 rather than ignore the new model. If I already owned the original, as I do, I would upgrade only for a concrete missing capability. The original KeyStep 37 remains the best 37-key controller I have personally found because its feel, size, and standalone musical tools all get used.
Sources and currency
Product details were checked against the following first-party pages on August 28, 2026. My workflow judgments are based on the experience described above.
- Original Arturia KeyStep 37: keybed, sequencer, arpeggiator, chord, controller, MIDI, sync, and CV features
- Arturia KeyStep 37 mk2: the current 2026 model and its expanded pattern, display, generative, USB-C, MIDI, and CV features
- Arturia KeyStep 37 mk2 questions: the current model's generative, pattern-memory, display, USB-C, MIDI, and CV details