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Core Concepts

By the Forma Labs teamUpdated March 2026

Filament separates the musical behavior you perform from the hosted instruments that make sound. These terms are the map for the manual.

Keyswitch

A performance slot that stores one orchestration state. Switching keyswitches changes voice layers, routing, modules, clips, arpeggiators, and articulation trigger choices while keeping the mixer and hosted instruments loaded.

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Voice Layer

One of eight input processors inside a keyswitch. Voice layers filter, split, isolate, or revoice incoming MIDI before it reaches the routing matrix.

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Routing Matrix

The grid that connects the eight voice layers to output rows. Each connection can have its own transpose value.

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Output Row

A row that receives processed MIDI and applies per-row modules before sending the result to a hosted plugin, host MIDI output, or no destination.

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Modular Presets and Full Setups

Filament's preset system can either recall the whole working state as a Full Setup, or keep the structure, hosted instruments, and musical behavior separate so they can be recombined.

During performance, MIDI passes through the active keyswitch's voice layers, routing matrix, and output row modules. The output row then sends the result to a hosted plugin or host MIDI output.

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