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Arturia KeyStep Pro

Arturia KeyStep Pro

Arturia's KeyStep Pro puts sequencing and performance front and centre.

It's been over four years since Arturia whipped the dust cover off their KeyStep polyphonic sequencing keyboard. Most of us supposed that a bigger, multichannel version would have followed on its heels, matching what happened with the BeatStep. In the interim, just about everyone has bought a KeyStep, and the stopgap Pro option was, well, two KeySteps.

It's not just the CV outputs and sequencer that have made the KeyStep such a popular companion to hardware synth rigs. It's also pretty much the only super-mini that's got MIDI ports as well as USB, and so isn't reliant on a computer or other USB host. But while the KeyStep is great as a portable controller, or as an add-on keyboard for a single instrument, it's not a performance and sequencing hub for several devices. But the KeyStep Pro certainly is!

I've Got The Key

The KeyStep Pro is a four-part MIDI/CV sequencer and controller, with a three-octave mini keyboard and five touch-sensitive encoders. All four parts can operate as polyphonic note sequencers running patterns up to 64 steps long. One of these parts can be switched into a drum mode with 24 trigger lanes. The other three parts toggle between sequencer and arpeggiator modes. An additional Control channel lets you generate and automate MIDI CCs with the encoders.

Many of the specs exceed those of the BeatStep Pro: 24 drum tracks instead of 16 and three polyphonic note parts instead of two monophonic. And this is without sacrificing connectivity. You still get analogue trigger outs for the first eight drums, and there are now four voices worth of CV outputs. The two MIDI outputs are full-sized. The analogue clock connections are joined by a Reset output.

...while the KeyStep is great as a portable controller, or as an add-on keyboard for a single instrument, it's not a performance and sequencing hub for several devices. But the KeyStep Pro certainly is!

Accommodating keys instead of pads makes the KeyStep Pro a fair bit larger than the BeatStep Pro, but it still looked tiny in the space where my regular keyboard controller sits. The keys share the bottom half of the surface with some mode buttons and modulation touchstrips. The keys have monophonic aftertouch and key lights which are really handy for seeing what notes are stored on sequencer steps. Above the keys are 16 step buttons and individual colour-coded panels for each of the four tracks. This top control section also has a master panel for project and settings management and transport.

While we're browsing panel features, special mention must go to the metronome. This is part of a dedicated tempo and timing section, with encoders for tempo and swing, and a tap-tempo pad. The stroke of genius here was including a small built-in speaker for the metronome, with a pop-out level knob on the rear of the unit. It's a drag on standalone sequencers when you have to set up an external click source.

Hooking Up

The KSP's bountiful connectivity means there are myriad ways you could build a setup around it. I tried a few different scenarios, starting with an Ableton-centric DAW configuration. I had the KSP chasing MIDI clock from Live, while sequencing a Live Drum Rack over USB, a Novation Circuit over MIDI and a desktop semi-modular via CV/Gate. The KeyStep was sequencing the latter, but in this setup I could have sequenced it from Live itself, using the KeyStep as a MIDI-to-CV convertor.

I also patched up a DAW-less rig that proved so fun that it stayed in place for the rest of the review. I had USB connected to an MPC, MIDI to an Elektron synth and Octatrack and one of the drum triggers going to the 0-Coast just for kicks (you see what I did there?) This time the KeyStep Pro was my central clock source, and in fact controlled the MPC's transport via MIDI Machine Control with zero menu-diving on my part. A 303 rounded out this setup, driven by the KeyStep Pro's clock output. The only bump in the road was discovering that the two MIDI Outs are not separate ports — they provide a duplicate output. This is handy for patching, but does mean you need to set discrete channels even with just one device on each port.

Making Tracks

Selecting a track from the top panel focuses the KeyStep on that part. The keys and mod strips will then point to that output, and that sequencer track will be available for entry and editing. Alternatively you can create a temporary keyboard split by pressing two Track buttons at the same time, and selecting a split point.

Other than Track 1, the parts are toggled between Arp and Seq modes. Arpeggiation is a discrete mode, used as an alternative to sequencing. In fact you can flip in real time between an Arp pattern that's locked in with the Hold button, and a Sequence on the same Track (and can cue up or edit Patterns in the background while the Arp plays). The arpeggiators are really versatile, with multiple playback directions, ranges and speeds. I particularly enjoyed the Poly Arp mode which arpeggiates block chords through the selected octave range. It's just a shame you can't run the sequencer into the arpeggiator, though, like you can on Elektron's sequencers.

On the sequencing side, all three classic entry methods are available. Real-time recording, happily, can be unquantised, and you can toggle between overdub and overwrite behaviours. If you arm recording while stopped, you're in step entry mode, where playing a note will store it and advance to the next step. There are a couple of upgrades here over a typical 101-style sequencer: note entries can be polyphonic (up to 16 notes), and you can back up or jump to a different place just by tapping the step buttons.

This works differently to the original KeyStep, where the number of notes you enter determines the sequence length, and where you can append notes during playback. Instead, with the KeyStep Pro you are always writing into pattern slots with manually set lengths.

This structure, however, opens up masses more sequencing potential that users of the BSP and Brute drum machines will be familiar with. Patterns can be built using the familiar 'press and play' method of holding a step and playing the required notes on the keyboard. Once you've created a Pattern there's an array of transformations available as secondary functions on the step buttons, from adjusting length, transposing (in key), inverting, nudging and more. These destructive (but undoable) operations are complemented by a number of Shift functions on the note keys which mess with playback order and speed.

Compact at 589 x 208 x 38 mm, the KeyStep Pro nevertheless weighs a chunky 2.7kg.Compact at 589 x 208 x 38 mm, the KeyStep Pro nevertheless weighs a chunky 2.7kg.


In Drum mode, Track 1 is split out into 24 individually editable gate lanes. These are sent out as 24 MIDI notes, with the first eight also hitting the analogue drum gate outputs. A global setting maps which MIDI note the Drum sequencer starts on, so you can line it up with whatever instrument or plug‑in you're playing. The fact that this is a global setting not stored with Projects proved frustrating a couple of times.

Drum sequences can be recorded in real time via the keys, or you can drop gates on the Step buttons. Each drum voice can be brought up separately on the Step section by pressing its key. You can even mute individual lanes by holding Mute and pressing a key, and you can lock in a performance-friendly mute mode where simply pressing keys mutes sounds.

Cleverly, a mode toggle that switches regular sequences between Mono and Poly modes is used in Drum mode to enable polymetric mode. When enabled, you can set a different pattern length for each drum subtrack.

In most respects, then, the drum sequencer is as powerful as the one found on the BeatStep Pro and Arturia's analogue drum machines. There is a slight difference in the Randomness features. The BSP has both Randomness and Probability controls, and the DrumBrutes are able to apply Pattern-wide randomisation (one of my favourite features on those machines). The KSP instead has a single Randomness knob, which in Drum mode sets a probability on a per-event basis, similar to Elektron's Conditional Trig feature.

When sequencing drums I usually like to populate a few pattern slots with variations of the main beat. The lack of a simple Duplicate function on Arturia's sequencers slows things down a bit here. To move to a new variation is a three-step process — Copy, Paste, Launch — with each step a multi-button combo. But it's worth the effort, because you can then perform quick variations and fills via Pattern flipping, or by creating Pattern Chains.

A great way to generate impromptu fills and variations is the Looper, another feature in common with the BSP and Brutes. This is triggered by a dedicated touchstrip, and freezes all sequences in a loop of 1/4th, 1/8th, 1/16th or 1/32nd note length. On release, playback resumes at the point it would have reached if uninterrupted. The loop position can even be moved by pressing Step buttons.

Note Properties & Control

Three of the five encoders adjust step parameters, namely Pitch, Gate Length and Velocity. The other two adjust timing and randomness. In Arp mode, these are dynamic controls that affect notes as they play (Randomness adding in extra notes). In Seq mode, the dials are used to edit individual steps, and Randomness sets the percentage chance of a particular step triggering.

In Seq mode, before recording, the encoders set the default values for new notes. If you subsequently hold a step you can edit its parameters in isolation. This all works well, and provides an alternative 'knobular' method for entering note sequences, but there are a some frustrating limitations. I regularly wanted to adjust one of the parameters, say gate length, for a whole existing sequence, but you can't. Neither can you hold more than one step at a time for editing. And you also can't capture adjustments in real time unless you're recording notes at the same time.

On a somewhat related note, the Sequence tracks have limited modulation control or automation beyond the per-step storing of note/gate properties. You get the mod wheel (strip), which provides a single, assignable MIDI CC source per track, plus aftertouch. But there are no other CC controls available within the Tracks.

The combination of structural arrangement features and deep real-time pattern tweaking makes the KeyStep Pro a versatile and inspiring performance sequencer.

MIDI CC Control and automation is instead provided as a single separate Control track, complete with its own bank of pattern slots. While in Control mode, the five encoders transmit modulation on assignable MIDI CC channels. (The keyboard continues to play whichever regular Track was previously active). Parameters on the Control track can be automated both in real time and per step.

There are times when it could be useful and creative to have control and modulation separate to your note sequences. However, in most sequencing or live performance scenarios I'd rather have independent CC control maps as part of each regular track, and recorded within track patterns. Five controls to share among the four tracks is also a bit underpowered, and the assigned CC parameters are global, not stored with your Project.

Organising Your Ideas

The KeyStep Pro can keep 16 Projects onboard at a time. These can be backed up and loaded via Arturia's MIDI Control Center utility. Projects store 16 Patterns for each Track, along with 16 Scenes.

Arturia's MIDI Control Center software gives you a clear overview of what's going on and allows you to back up projects.Arturia's MIDI Control Center software gives you a clear overview of what's going on and allows you to back up projects.

Patterns are the basic building blocks, with anything from 1 to 64 steps. As on the BeatStep Pro, each Track panel has a display showing the current Pattern, with up/down buttons for selection. Better still you can hold the Pattern button and jump directly to a specific Pattern via the Step buttons. Pattern switching can be queued, or can pick up instantly in step (which I always prefer). Scene and Project launching is sadly always from the beginning, but at least you can seamlessly load songs, unlike some other hardware sequencers that should know better.

Each track can also store a single Chain: a sequence of Patterns up to 16 steps long. Creating a chain is as simple as holding the Chain button and tapping the step buttons in the order you want Patterns to play. While Chain mode is active, the sequence of Patterns loops. Complete song structures can be assembled by creating Chains on each track, with empty Patterns used on Tracks where you want them to be silent.

Lastly you have Scenes. These are snapshots that recall which Pattern or Chain is active on each track, as well as Mute states. I found these provided a more improvisational method of generating a performance than programming multitrack Chains. Scenes also recall which Track was focused, which is handy for Live performances when you want to make sure you're playing the right sound.


The combination of structural arrangement features and deep real-time pattern tweaking makes the KeyStep Pro a versatile and inspiring performance sequencer. The fact that it's based around a keyboard and uses a fairly conventional layout makes it feel more immediate and accessible than much of the competition. It also of course wins big on connectivity, covering MIDI, USB, CV, triggers and clock! There are more capable dedicated sequencers, and as a live performance controller the mini keys and limited MIDI CC functionality might be an issue, but as a highly portable all-rounder the KeyStation Pro lands right in the sweet spot for an awful lot of us.


Live players may prefer the full-sized keys, superior MIDI CC control and recallable templates of Novation's SL MkIII. The extra money also buys you more tracks. If you prefer pads to keys, the Launchpad Pro has a similarly spec'ed sequencer to the KeyStep Pro. Arturia comfortably outgun both in terms of analogue connectivity, though.

A different question is whether the BeatStep Pro is closer to what you need. On paper the KeyStep Pro is more powerful as both a note and drum sequencer. However, the BeatStep's array of encoders give you richer MIDI control, and allows you to adjust pitch and other properties 16 steps at a time. It also has a Mackie Control mode.

Analogue Brain

Arturia KeyStep Pro rear connections.The KeyStep Pro's rear connections.

Short of a considerably more expensive dedicated Eurorack sequencer like a Squarp Hermod, or a CVIO expanded Cirklon, I can't think of anything that compares to the KeyStep Pro for analogue connectivity. Eight trigger outs, four voices of Pitch/Gate/Mod, and Clock makes for a versatile toolkit. Each sequencer track can be routed to any of the CV voice groups, giving four independent mono sequencers; but you can also assign multiple output sets to a track for up to four-voice polyphonic CV.

Each voice's Mod output can be switched between Velocity or Aftertouch. It's a shame you can't route the mod touchstrip or any of the Control mode encoders to the CV mod outputs. As it stands you'd need to dedicate another sequencer track to get a single extra mod source that's not tied to notes, but this could be implemented later.


  • Standalone, USB‑powered MIDI and CV control.
  • Multitrack, polyphonic sequencing on all formats.
  • Scenes and Chains.
  • Pattern variations and Looper.


  • No MIDI CC controls within tracks.
  • No assignable CV mod sources currently.
  • Projects don't store CC and drum map assignments.


The KeyStep Pro might have taken a while to get here, but it's burst out of the gate packed with features.