F_GENSEQ

F_GENSEQ – Generative Probability Sequencer

F_GENSEQ is a compact generative sequencer built around probability, repetition, and controlled randomness. Instead of programming fixed step values, F_GENSEQ generates evolving musical patterns from a fixed pool of notes, using probabilistic rules that shape when notes play, repeat, or remain silent.

The module is designed for generative melodies, evolving basslines, ambient sequences, and rhythmic pitch modulation. In WINDOW mode, variation is stable within a cycle and only changes when explicitly regenerated or when the window shifts. In PURE mode, the pitch is freshly randomized on every clock tick.

Clocking

F_GENSEQ can be driven by an external clock or by its internal clock. If the CLOCK input is connected, the external signal is used. If no cable is connected, the internal clock becomes active.

The internal clock speed is set using the BPM knob at the bottom. The DIV knob determines how this clock is subdivided or divided depending on whether you are using internal or external clock.

RESET

The RESET input reinitializes the sequencer state. It resets playback position and internal counters, and rebuilds the internal random content that drives the pattern.

In WINDOW mode this means the 64-step note pool is regenerated and the step probability distribution (the fixed random value per step) is refreshed, so the pattern starts over with a new “random DNA.” In PURE mode, RESET also refreshes the random state so the stream of pitches changes character immediately.

Use RESET when you want a hard restart and a new pattern at the same time.

PAUSE

The PAUSE button freezes the sequencer immediately. While paused, the module stops responding to clock pulses, stops emitting gates, and holds the last generated pitch at the PITCH output. This is useful for “momentary silence” without losing your place.

PAUSE can also be controlled via the MOD matrix when a MOD slot is assigned to Pause. In that case the Pause state is driven by the incoming modulation signal and the PAUSE button will follow the modulated state visually.

Modes

F_GENSEQ operates in two modes selected by the MODE switch at the bottom.

PURE Mode

In PURE mode, each clock pulse generates a new random pitch within the selected range. No 64-step pool or window is used. This mode is ideal for continuously evolving random melodies and “always different” modulation lines.

WINDOW Mode

In WINDOW mode, F_GENSEQ generates a fixed pool of 64 random notes. A movable window scans across this pool, producing repeating but slowly shifting patterns. This is where the module feels most like a musical sequencer: it repeats, but it also evolves.

WIN (Window Length)

The WIN knob sets how many steps are played from the pool before the window loops. Short windows create repeating motifs, while longer windows feel more linear and melodic. WIN can be modulated via the MOD matrix when a typical slot is assigned to Window.

HOLD (Cycles)

The HOLD knob determines how many full window cycles are repeated before the window position shifts. Increasing HOLD stabilizes patterns and slows harmonic motion. HOLD can be set from 1 to 32 cycles. Special values are available: HOLD = 0 means the window never shifts, and HOLD = -1 selects a random hold length (a new random cycle count is chosen when the window shifts). HOLD can be modulated via the MOD matrix when assigned to Hold.

SHIFT

The SHIFT knob controls how far the window moves through the 64-step pool after the HOLD count is reached. Larger values cause more dramatic melodic changes. SHIFT can be modulated via the MOD matrix when assigned to Shift.

Probability Controls

PLAY

The PLAY knob is the global probability that a step will produce a note. Even if a step is otherwise enabled, it will only fire if this probability test succeeds. PLAY introduces rhythmic variation and sparse textures. PLAY can be modulated via the MOD matrix when assigned to Play Prob.

RAND

The RAND knob sets the probability that, in WINDOW mode, a step ignores the window note and plays a completely random note instead. This adds controlled chaos on top of structured patterns. RAND can be modulated via the MOD matrix when assigned to Rand Prob.

PROB

The STEP PROB knob does not change the note pattern itself. Instead, each step has a fixed random value assigned when the step distribution is generated. STEP PROB acts as a threshold: steps whose random value exceeds the knob setting are muted.

This means you can turn STEP PROB up or down live without altering the underlying pattern. Use the REGEN button to generate a new step distribution. STEP PROB can be modulated via the MOD matrix when assigned to Step Prob.

Pitch Generation

RNG (Range)

The RNG knob sets the pitch range in octaves for both random note generation and the note pool. A value of 0 still produces at least one octave to avoid silence. RNG can be modulated via the MOD matrix when assigned to Range.

SCALE

The SCALE knob enables optional pitch quantization. When set to OFF, pitches are chromatic. Other positions constrain notes to musical scales, interval-based sets (such as Power and Sus chords), and chord structures (such as Major 7, Minor 7, and Dominant 7), depending on the selected mode. SCALE can be modulated via the MOD matrix when assigned to Scale.

ROOT

The ROOT knob sets the key center for quantization (C through B). When SCALE is OFF, ROOT has no effect. When SCALE is enabled, ROOT transposes the quantizer so the same scale shape can be played in different keys. ROOT can be modulated via the MOD matrix when assigned to Root.

TRANSPOSE (Modulation Target)

TRANSPOSE is a dedicated modulation target that applies true pitch transposition in semitones after note generation and before quantization. It is designed for musical pitch shifting using standard 1V/octave control voltages.

When a MOD slot is assigned to Transpose, the incoming CV is interpreted as 1V per octave. A modulation value of +1.0V transposes the output pitch up by exactly one octave (+12 semitones). Negative voltages transpose the pitch downward.

TRANSPOSE affects the absolute pitch height but does not change the selected scale or key. Quantization remains active after transposition, so pitches stay constrained to the selected SCALE and ROOT unless SCALE is set to OFF.

This makes TRANSPOSE ideal for melodic octave shifts, key-relative pitch modulation, keyboard tracking, or slow harmonic movement driven by LFOs, envelopes, or sequencers.

TRANSPOSE works in both normal operation and TEST mode. In TEST mode it allows verification of scale behaviour across multiple octaves while keeping the same scale structure.

Note that TRANSPOSE is intentionally separate from ROOT. ROOT defines the musical key (pitch class), while TRANSPOSE shifts the pitch up or down in octaves. Modulating ROOT changes which notes belong to the scale; modulating TRANSPOSE changes where those notes are played in pitch space.

BPM

The BPM knob sets the tempo of the internal clock in beats per minute. This value is ignored when an external clock is connected. BPM can also be modulated via the MOD matrix when a MOD slot is assigned to BPM.

DIV

The DIV knob selects musical time scaling in powers of two: 1x, 2x, 4x, 8x, 16x, or 32x.

When using the internal clock, DIV multiplies the clock speed, creating rhythmic subdivisions. When using an external clock, DIV divides the incoming clock, producing one output trigger every N input pulses. DIV can also be modulated via the MOD matrix when a MOD slot is assigned to Div.

MOD Matrix

F_GENSEQ includes 8 modulation slots. Each slot has a CV input jack and an assign button. Click the assign button to open a dropdown and choose a destination. The CV input is read as raw volts; use an external attenuator/attenuverter if you want fine scaling.

Typical modulation targets include BPM, Rate, Root, Scale, Window, Hold, Shift, Play Prob, Rand Prob, Range, Step Prob, Pause and Transpose. Multiple slots can target the same parameter; their voltages are summed.

Outputs

PITCH

The PITCH output sends a 1V/oct control voltage corresponding to the generated note. The value is latched and held until the next note event, and it remains held while PAUSE is active.

GATE

The GATE output produces a short trigger pulse whenever a note event occurs. While paused, the gate output stays low.

Visual Feedback

The TRIG LED lights whenever a gate pulse is active. The MODE LED indicates whether WINDOW mode is enabled.

Typical Use Cases

Use PURE mode with low PLAY probability for evolving ambient textures. Use WINDOW mode with moderate HOLD and small SHIFT values for melodic loops that slowly mutate. Combine STEP PROB and PLAY for rhythmic variation without destroying musical structure. Use RAND sparingly to add surprise without losing the motif. Use external clocks for tight synchronization or the internal clock for self-contained generative patches. Use PAUSE (or modulated Pause) to stop motion instantly while keeping the current pitch held, which is useful for live patch performance and breakdowns.

Design Philosophy

F_GENSEQ is not a traditional step sequencer. It is a probability-driven musical system where structure and randomness coexist. The goal is not exact repetition, but controlled evolution.

TEST Mode (Scale Verification)

The TEST switch (located next to the MODE switch) enables a deterministic verification mode for pitch quantization, scale definitions, interval sets, and chord structures.

When TEST is OFF, F_GENSEQ operates normally using random note generation, probability logic, windowing, modulation, and regeneration.

When TEST is ON, all randomness is disabled. Notes are no longer selected from the random pool. Instead, pitches are generated in a fixed, repeatable order derived from the selected SCALE and ROOT.

TEST mode has two positions:

TEST = 1 (Scale Step)

In this mode, F_GENSEQ steps sequentially through the notes allowed by the selected SCALE or chord set, starting at ROOT. For example, a Major scale will play 1–2–3–4–5–6–7 in order, while a Power scale will alternate between 1 and 5, and a Dominant 7 chord will cycle through 1–3–5–b7.

The WIN control (and MOD_WIN) limits how many scale or chord tones are looped before repeating, allowing focused inspection of subsets within a scale or chord.

TEST = 2 (Chromatic → Quantize)

In this mode, F_GENSEQ plays a chromatic sequence (0 up to WIN−1 semitones from ROOT) and then applies the active quantizer. This reveals how incoming pitches are mapped to the selected SCALE or chord structure, making it easy to detect incorrect quantization or unintended overlaps.

Active in TEST mode: ROOT (including modulation), SCALE selection, WIN (including modulation), clocking, pitch output.

Ignored in TEST mode: PLAY, RAND, STEP PROB, HOLD, SHIFT, regeneration logic, and all probabilistic behaviour.

TEST mode is fully independent from the generative engine and does not alter any stored random content. Switching TEST OFF immediately returns F_GENSEQ to normal generative operation without changing the current pattern.

TEST mode is especially useful for validating sparse interval sets (such as Power, Sus2, Sus4), chord-based scales (Major 7, Minor 7, Dominant 7, etc.), and custom harmonic structures where randomness could otherwise mask errors.