Compact 4-Voice Polyphonic Analog Synthesizer

Fourm delivers four genuine voices of Sequential analog sound, built on the legendary Prophet-5 voice architecture-right down to its envelope response curves. With dual oscillators offering simultaneous wave selection and a classic 4-pole low-pass filter, now enhanced with bass compensation, Fourm captures the warmth and punch that shaped a generation-and takes it to the next level.

Fourm's 37-note slim-key keyboard features polyphonic aftertouch, unlocking expressive techniques like guitar-style note bends, solo voice swells, and other nuanced articulations-completely transforming the experience of playing a modern analog polysynth.

Inspired by the Pro~One, Fourm's top-panel modulation matrix puts deep sound design at your fingertips-no menu diving required. Route sources and destinations with a button press, visualize connections with color-coded indicators, and build complex modulation paths in seconds. It's fast, intuitive, and designed to keep you in the creative flow.

Custom-designed by Sequential, the Tactive™ keybed features 37 slim-keys tuned specifically to complement Fourm’sanalog synthesis engine. And for the first time in 40 years, Sequential has returned to polyphonic aftertouch, an incredibly expressive performance feature that brings per note articulations to your fingertips.

Polyphonic aftertouch is one of Fourm’smost expressive features, offering a direct and nuanced connection between your playing and per note synthesis parameters. It opens up new possibilities for articulation — from subtle dynamics to dramatic gestures — that go far beyond what’spossible with other high performance musical instruments and controllers.