Note Track — manual

The core melodic sequencer. Sixteen steps per pattern, each a stack of per-step layers — pitch, gate, length, probability, retrigger, slide, condition — over sequence-wide scale/timing and track-wide octave/bias params.

Introduction

The Note track is the most-featured track in xformer: every other track type borrows its timing, scale, and routing conventions from here. A Note step is not a single value — it is a stack of per-step layers edited one at a time, plus sequence-wide params (scale, run mode, divisor) and track-wide params (octave, transpose, slide time, biases). The engine reads all of them every tick to decide whether the gate fires, how long, at what pitch, and how often.

Everything here is grounded in the firmware as built — defaults, ranges, enum members, key bindings, and step-grid maps come from the model, engine, and UI code.

Prerequisites

• Familiarity with the xformer track/sequence/edit page model (Page+S2 / Page+S1 / Page+S0).
• Understanding of CV/gate concepts in modular synthesis (1V/oct, gate high/low).
• A grasp of the scale/root-note system — the Note track quantizes its output to a scale.

Part 1 · Overview

A Note track holds many patterns (plus snapshot slots). Each pattern is a NoteSequence of 16 Steps. The active pattern plays; its loop window (firstStep..lastStep) is read each clock division according to the run mode.

Three scopes of state:

• Per-step note, gate, gate prob, gate offset, slide, retrigger + prob, length + variation, condition, accumulator trigger, pulse count, gate mode, harmony overrides. One value per step, per layer.
• Sequence-wide scale group (scale/root/rotate), divisor, clock mult, reset measure, run mode, first/last step, traversal mode (Linear / Re:Rene / Ikra). One set per pattern.
• Track-wide play mode, fill mode, CV update mode, slide time, octave, transpose, rotate, and four probability/length biases. Shared across all patterns.

How a step plays

Every divisor boundary the engine advances the sequence state, picks the current step, then runs it through, in order: condition check → gate probability → gate-mode/pulse logic → retrigger subdivision → length → note evaluation (variation + accumulator + harmony) → scale quantization → slide. The gate and CV are scheduled into sorted queues and emitted at the right tick with swing applied.

Part 2 · Per-Step Layers

Steps are edited one layer at a time. The five function keys group the layers; pressing a function key again cycles to the next layer in that group. Shift+F1..F5 jump directly to the primary layer of each group (Shift+F4 instead resets the accumulator runtime value).

The F4 group's tail depends on the sequence's harmony role: master sequences expose Inversion then Voicing; follower sequences expose Harmony Role; off sequences loop straight back to Note.

The same 16-step grid stays on screen as you cycle layers; only the cell drawn under each gate box and the highlighted footer key change. The header label echoes the active layer.

All per-step layers, defaults, ranges

Defaults are from Step::clear(). Ranges are the value-type bit widths.

Gate Mode and Pulse Count

Pulse Count holds one step across pulseCount + 1 divisor pulses. Gate Mode decides which of those pulses actually gate:

Conditions

The Condition layer gates the step on a runtime predicate. Pre/NotPre reference the previous conditional step's result; Fill references the fill state; First references iteration 0; Loop/NotLoop fire on every Nth loop with an offset.

Note quantization

The stored Note value is a scale degree (-63..+63, 0 = root). The engine adds octave + transpose, optional note variation, optional accumulator offset, optional harmony, then converts to volts through the selected scale. Chromatic scales add the root note as a 1/12 V offset; non-chromatic scales fold root into the scale lookup.

Part 3 · The Edit Page

Page+S0 (with the track selected) opens the STEPS edit page. The 16-step keypad maps to the current loop section; Left/Right move between four sections.

F-keys, encoder, Shift

• F1–F5 switch/cycle the active layer. The active function is shown in the header.
• Encoder edits the selected step(s) on the current layer. On Note/Note-Range layers, Shift + encoder jumps by a full octave (chromatic scales only).
• Encoder press toggles the gate of the selected steps (off if all selected are on, else on).
• Shift+F4 resets the accumulator runtime value (shows "ACCUM RESET").

Step keypad behaviour

• Tap a step (Gate layer) toggles its gate.
• Double-tap a step (any non-Gate layer) toggles its gate without leaving the layer.
• Hold a step + tap another range-selects; the encoder then edits all selected steps.
• Hold a step + F1–F5 sets that step's note to octave 1–5 (quick octave set).
• Shift + Left/Right shifts the selected steps (or the whole loop) left/right by one.

LED colours

• Current playing step: red.
• Selected steps: red + green (always green when selected).
• Gate layer: lit green where the step gate is on.
• Accumulator layer: lit green where the step has an accumulator trigger.
• Other layers: green follows the gate state.
• The four section LEDs show the selected sequence section.
• Holding Page (no Shift) lights S9–S16 green for the available quick-edit slots.

Context menu (long-press)

Part 4 · Timing & Traversal

Per-sequence timing params

Run modes

Types::RunMode: Forward, Backward, Pendulum, PingPong, Random, Random Walk.

Play mode (track-wide)

• Aligned (default) — steps advance on divisor boundaries phase-locked to the master clock; pulse-count and retriggers are honoured.
• Free — the step index is computed from the free-running clock position; allows Re:Rene and Ikra traversal.

Traversal modes (Mode)

• Linear — standard single-sequence playback.
• Re:Rene — an 8×8 X/Y grid walk (Free play mode only). X and Y advance on their own divisors; the Y divisor can be driven by another track's gate (Div Y Source = Gate, Div Y Track = T1..N). Steps outside first/last are skipped.
• Ikra — a second independent note loop (Note First/Note Last) advances on its own Div N divisor while the rhythm loop advances on Div X, so pitch and rhythm phase against each other.

Part 5 · Accumulator & Harmony

Accumulator

The accumulator adds a drifting offset to note pitch. It is a sequence-wide engine (enabled, min/max bounds, step value, direction, order) plus a per-step trigger value on the ACCUM layer:

• OFF (--) — step does not drive the accumulator.
• S — step uses the sequence's global step value.
• ±1..±7 — step overrides the step value (and sign flips direction) for that tick.

Trigger modes (sequence-wide) decide when the accumulator ticks: per Step (once per step, first pulse), per Gate (each gating pulse), or per Retrigger (each subdivision). Mode Stage applies the offset only to triggered steps; Track applies the current value to every step. Shift+F4 on the edit page resets the runtime value to its floor.

Defaults: step value 1, min 0, max 7, with Mode Track, Polarity Unipolar, Direction Up, Order Wrap, Trigger Step (enabled).

Harmony

A Note sequence has a harmony role: Off, Master, or one of four Follower roles (Root/3rd/5th/7th). A follower watches a master track (another Note track) and harmonizes the master's current note into a chord, then plays the chord tone for its role.

• Master settings: harmony scale/mode (0–6), inversion (0–3), voicing (0–3), transpose (±24 semitones). Per-step Inversion override available on the master.
• Follower: follows masterTrackIndex (0–7); role is the chord tone it plays. Per-step Harmony Role override available on the follower.

Part 6 · Output & Recording

CV update mode (track-wide)

• Gate (default) — CV updates only on gating steps.
• Always — CV updates every step even when the gate is muted.

Slide

Slide Time (track-wide, 0–100%) sets the glide time. A step's Slide flag makes the CV ramp from the previous note toward the new note over that time; without slide the CV jumps.

Fill (track-wide)

Fill Mode: None / Gates / Next Pattern / Condition. Fill replaces gates, swaps in the next pattern's sequence, or activates Fill-conditioned steps while fill is held. Fill Muted controls whether fill still applies when the track is muted.

Live & step recording

• Live recording captures incoming MIDI/CV into steps quantized to the divisor, writing gate, note, and length; in Overwrite record mode, ungated steps in the played window are cleared.
• Step recording advances a record cursor; played notes write one step at a time.
• Monitoring — selecting a step on the Note layer (when stopped) sounds it; live MIDI input can be monitored per the project monitor mode.

Part 7 · Setup & Routing

Track-scope list (Page+S2)

Track-wide params, hosted by the generic Track page (NoteTrackListModel):

Sequence-scope list (Page+S1)

Per-pattern params (NoteSequenceListModel); rows shown depend on Mode:

• Linear: Mode, First Step, Last Step, Run Mode, Div X, Clock Mult, Reset Measure, Scale, Root Note, Scale Rotate.
• Re:Rene adds: Div Y, Y Src, Y Trk.
• Ikra adds: Note First, Note Last, Div N.

The quick-edit overlay (Page + S9–S16 on the edit page) exposes, in order: First Step, Last Step, Run Mode, Div X, Reset Measure, Scale, Root Note.

What is routable

Track-scope routing targets:

• SlideTime, Octave, Transpose, Rotate
• GateProbabilityBias, RetriggerProbabilityBias, LengthBias, NoteProbabilityBias

Sequence-scope routing targets:

• FirstStep, LastStep, RunMode, Divisor, ClockMult, Scale, RootNote

Per-step layers (note, gate, length, condition, etc.) are not routable — they are step data, edited on the grid, not modulation targets.