When a new synthesizer from Sequential lands, the entire music community takes notice. With the FOURM, the American brand makes a bold statement. This compact 37-key model blends the legendary warmth of the Prophet-5 with innovations designed for today’s musicians. Expressive keyboard, intuitive modulation, robust design: everything is geared toward unleashing creativity.
Let’s dive into the FOURM’s features, what sets it apart from other analog synthesizers, and why it might just become a future classic in studios and on stage!
The return of Sequential’s legendary sound
Sequential is not just any brand. Founded by Dave Smith, it gave us iconic instruments that shaped modern electronic music, from the Prophet-5 to the Pro-One. The FOURM follows in that tradition, offering a 4-voice sound engine directly inspired by the Prophet-5.
- Two oscillators per voice: capable of generating multiple waveforms simultaneously.
- 4-pole resonant low-pass filter: a classic, with a welcome upgrade — bass compensation.
- Feedback with drive circuit: for a more aggressive, organic character.
The result? A punchy, warm sound that breathes analog and retains the unique depth that defines Sequential instruments.
If you’re looking to recreate vintage textures à la Vangelis, the FOURM is an ideal partner. But it also shines in modern contexts thanks to its wide modulation palette.
A new “FOURM” of expression: the poly-aftertouch keyboard
This is arguably the innovation musicians will notice most. The FOURM’s slim 37-key keyboard features polyphonic aftertouch. In practice, this means each key can transmit independent modulation depending on pressure.
This allows you to:
- Add bendings worthy of a guitar.
- Create progressive swells on certain chords.
- Play with an expressiveness impossible on a standard keyboard.
This technology is still rare in compact analog synths. Sequential has successfully bridged tradition and modernity.
Polyphonic aftertouch is close to what some MPE (MIDI Polyphonic Expression) keyboards offer. But here, no need for exotic surfaces: it’s built right into a practical keyboard format.
Modulation at your fingertips
No more labyrinthine menus: the FOURM’s modulation matrix is right on the front panel. Inspired by the Pro-One, it’s designed for live performance as well as fast sound design.
- Select sources and destinations with a simple press.
- See connections via color-coded indicators.
- Build complex routings in seconds.
This approach gives the FOURM a flexibility comparable to modular synths, but in a plug-and-play format.
Combine oscillators as modulation sources with the resonant filter as a destination to create metallic, evolving textures perfect for experimental electronic music.
Built-in arpeggiator and sequencer
No modern synth is complete without a solid built-in composition tool. Sequential delivers with an arpeggiator paired with a sequencer mode.
- The arpeggiator transforms a simple chord into an instantly inspiring rhythmic line.
- The step sequencer with glide gives precise control for hypnotic patterns.
These features are ideal for electronic musicians, but also for film and game composers looking to craft evolving atmospheres.
An ergonomics designed for musicians
Sequential has always prided itself on clear, straightforward interfaces. The FOURM stays true to this philosophy:
- One knob = one function: no need to dive into menus.
- Intuitive layout: oscillator, filter, envelope, modulation, and arpeggiator sections are instantly recognizable.
- Steel chassis: road-ready and built to last.
Weighing just 3.97 kg, it’s as portable as a MIDI controller while offering far superior sonic power.
Main technical features of the Sequential FOURM
A powerful synthesis engine
Each voice is based on two oscillators capable of layering multiple waveforms. Oscillator B can also act as an LFO. The 4-pole low-pass filter now comes with bass compensation, plus a feedback/drive circuit for more aggressive textures. Two ADSR envelopes and step glide complete the arsenal.
- Wave stacking for rich timbres.
- Resonance without bass loss.
- Feedback/drive for grittier tones.
An expressive keyboard
With its 37 slim keys and polyphonic aftertouch, the FOURM unlocks new playing possibilities. Each note can transmit independent modulation, perfect for adding depth to performances.
- Per-note bends.
- Progressive swells on chords.
- Filter nuances applied to a single voice.
Modulation and creativity
The front-panel modulation matrix lets you route sources and destinations instantly, with clear, color-coded feedback. Add in an arpeggiator, a step sequencer, and 128 presets, and you’ve got an immediate playground for exploration.
Connectivity and build
The FOURM offers a full set of connections (6.35 mm jack, headphone out, MIDI In/Out/Thru, USB MIDI, expression pedal) inside a sturdy steel chassis. Weighing just 3.97 kg with universal power supply, it’s as convenient on the go as it is in the studio.
Who is it for?
The FOURM speaks to a wide audience:
- Electronic music producers: for its powerful analog sound and intuitive modulation.
- Stage keyboardists: thanks to its compact format and unique polyphonic aftertouch.
- Composers: for its ability to generate expressive textures, perfect for soundtracks.
- Vintage lovers: who want to rediscover the Prophet-5’s character in a modern instrument.
In short, the FOURM sits right between a stage synth and a studio powerhouse.
Sequential FOURM vs other analog synthesizers
To better understand this newcomer, let’s compare it briefly:
- Versus the Prophet-5: it carries the same sonic philosophy, but in a more compact, affordable, and flexible format.
- Versus compact competitors: while many settle for basic keyboards, the FOURM stands out with polyphonic aftertouch and an intuitive modulation matrix.
- Versus digital synths: it retains the irreplaceable analog warmth and organic feel.
Conclusion: a future classic by Sequential
With the FOURM, Sequential achieves a real feat: condensing the Prophet-5’s sonic DNA into a compact instrument while adding major innovations like polyphonic aftertouch and an intuitive modulation matrix. It’s both a tribute to the past and a step toward the future. For musicians seeking expressiveness and sonic power, it may well become essential!
