TT-LuckyMidiChance — User Manual

01The concept

TT-LuckyMidiChance sits between your MIDI source and the instrument and decides — note by note — what happens to each event. It is not a random filter that gives different results every run: every stochastic decision comes from an internal XorShift32 PRNG, and the stream is fully determined by SEED. A locked seed produces an identical performance on every play, bounce and project reload; seed 0 runs free.

The unit is operated entirely from its drawn front panel (680×440, Tim Techlor design) — all 45 JSFX sliders are hidden by release policy but stay alive as the parameter/automation channel. The verdict chain per incoming note-on:

note on
  → COND      bar-position gate   (host transport timeline)
  → EUCLID    step-pattern gate   (16th-note grid)
  → CHANCE    probability gate    (seeded draw)
  → MUTATE    per-note hit        (flip / velocity / division)
  → DEVIATE   velocity ±VEL DEV, delay +0…TIME DEV
  → STRUM     chord-window spread (rank × TIME)
  → RATCHET   replaces the note by a K-hit burst in one 16th
  → QUEUE     time-sorted output, note-off tracking

Events stay on their input channel — no MPE remapping, so drum racks and monosynths keep working — and the plug-in adds zero latency: every delay it creates is a scheduled event offset inside the MIDI stream.

02Quick start

1. Insert TT-LuckyMidiChance before the instrument in the track's FX chain (it is a MIDI-only FX — no audio passes through).
2. Make sure the header button reads ENABLED (click toggles to BYPASS).
3. Leave SEED at 0000 (LED green = FREE) for fresh variation every pass, or dial in any number 1–9999 to lock a performance (LED amber = LOCKED).
4. Start with CHANCE ≈ 70 and VEL DEV ≈ 12 — instant organic feel without touching your part.
5. Add RATCHET DIV 1/8 or 1/16 for trap-style rolls, or set EUCLID PULSES/STEPS to gate notes onto a rhythmic pattern.
6. Short on time? Pick one of the five factory presets in the preset bar (Subtle Human is a good start) and save your own settings with SAVE.

03The front panel

Everything you touch is drawn by the plug-in — there is no slider page. Layout top to bottom:

HEADER

Wordmark LUCKY MIDI CHANCE; to its right the preset bar and the OPTIONS button, at the far right the ENABLED/BYPASS button. The second header row holds the seed LED (green FREE / amber LOCKED) and the SEED readout box with − + and FREE buttons. Mouse wheel over the readout steps ±1 (Shift = ±10), right-click resets to 0.

PROBABILITY

Top left: CHANCE knob, the COND cycler (< name >, click or wheel to step through 11 states), the COND CYCLE buttons 2/4/8/16 and the PASS (green) / DROP (amber) verdict LEDs.

BURST & SPREAD

Top right: STRUM TIME knob, UP/DOWN/ALT/RAND buttons; RATCHET division buttons OFF…1/16 and the DECAY % knob.

HUMAN DEVIATE

Bottom left: VEL DEV and TIME DEV knobs plus two live range bars that pulse with every passed note.

EUCLID & MUTATE

Bottom right: status readout (E(k,n) Rr or BYPASS), the PULSES/STEPS/ROTATE knobs, up to 32 step LEDs, the MUTATE AMT knob with value and the CHNC/VEL/RATCH/ALL target buttons.

READOUTS

Bottom strip: EV IN, EV OUT, EV DROP counters, Q LOAD number and bar (turns amber above 384 of 512 queue slots), and the legend line MIDI IN > CHANCE > COND > EUCLID > STRUM > RATCHET > OUT.

04Preset bar & user bank

The bar loads and saves the whole musical setting of the instance in one step: SEED, CHANCE, the condition mode and cycle, strum time and direction, ratchet division and decay, velocity and time deviation, the three Euclid values and the mutate amount and target (parameters 2–16). Not part of a preset: the ENABLED/BYPASS switch (a preset must never silence the track), the colour scheme (OPTIONS) and the hidden diagnostic and test parameters.

A factory preset starts from the defaults (INIT) and changes only the listed parameters, so it never inherits settings from what you had before. ENABLED and the colour stay as they are.

Where the user bank lives. Plug-ins cannot write files, so the 32 user slots are part of the plug-in state: they are saved with the project, with FX-chain and track-template copies, and in every REAPER preset of this plug-in (the + button in the FX window toolbar). To take your bank to another project or computer, save a REAPER preset once (+ → Save preset) and load it there: the whole bank comes with it. Projects saved with earlier versions load unchanged with an empty bank.

Typing names. REAPER keeps Space for the transport, so type Shift+Space for a blank. Depending on your REAPER settings Esc closes the whole FX window; use CANCEL instead. (The + menu of the FX window also has Send all keyboard input to plug-in.)

The preset bar is narrower than in the larger plug-ins (194 instead of 250 units) to fit the 680×440 header; long names are shortened with .. in the bar and shown in full in the list.

05SEED: FREE & LOCKED

The PRNG is re-seeded on every transport start and immediately when you change SEED in the panel, so A/B-ing two seeds is instant. With a locked seed, the same input after play start always yields bit-identical decisions — the same notes drop, the same strums roll, the same mutations hit. Change one digit and the performance changes completely.

Note: MUTATE hits, DEVIATE jitter and RAND strums all draw from this one stream — a locked seed locks everything, not just CHANCE.

06CHANCE: probability gate

At 100 the gate is open and costs no random draw. Below 100, dropped notes are removed completely — their note-off is swallowed too, so nothing hangs. The PASS (green) and DROP (amber) LEDs in the PROBABILITY panel flash with every verdict.

07COND: bar conditions

COND gates notes by where in the song they land — it reads the host transport, not the clip. The cycler steps (and wraps) through 11 states:

The COND CYCLE buttons (2 / 4 / 8 / 16 bars) set the cycle length used by FILL, !FILL and LAST — the 1:2…4:4 modes have their own fixed 2- or 4-bar grid. Two honest details: bars are counted on the project timeline (bar position in the song, time-signature aware), and with the transport stopped COND passes everything, exactly like OFF.

08STRUM & RATCHET

Strum note-offs are delayed by the same amount as their ons — chords stay intact, just rolled. A chord arriving across an audio-block boundary still joins the open window. Ratchet bursts consist of note-on/note-off pairs (off halfway to the next hit) and every hit counts in EV OUT.

09DEVIATE: human jitter

The two range bars under the knobs show the live ± window and pulse brighter with every note that passes. Both jitter sources draw from the master seed — a locked seed gives you the same “human” player every time, dragging and pushing identically on each bounce.

10EUCLID pattern gate

EUCLID is a gate, not a generator: it distributes PULSES hits over a STEPS-long ring using the Bjorklund algorithm — the same maximally-even distribution as every classic Euclidean box — and lets a note pass only when its onset lands on a pulse step of the 16th-note grid. ROTATE shifts which step the pattern starts on.

While transport plays, the step is the project's 16th-note position — the pattern repeats every STEPS sixteenths across the timeline. With transport stopped, a step counter advances per played note group (notes closer than ~15 ms share a step), so live playing is gated too. Notes on the same step share the verdict — a chord passes or drops together.

The step LEDs show the rotated pattern (acid dot = pulse, white ring = current step). Classic references: E(3,8) = x..x..x., E(5,8) = x.xx.xx., E(7,16) = x..x.x.x..x.x.x.

11MUTATE

MUTATE is a per-note seeded dice roll, not a slow drift: every note-on draws once against MUTATE AMT; on a hit, the chosen target is perturbed for that note only.

MUTATE AMT (0–100 %) is the hit probability — low values give occasional “wrong” notes, high values reorganise whole passages. COND is never mutated: the bar condition is a hard rule. Like everything else, mutation is fully seeded — a locked SEED replays the same hits.

12In practice

Three recipes that show how the modules are meant to work together. Every control named here is documented in the sections above — what matters here is the order of moves and what to watch while it runs.

1 · A real-player lane — humanize only

Goal: make a quantized keys, pad or drum lane feel played without losing a single note.

1. Leave CHANCE at 100, EUCLID PULSES at 0 (BYPASS), RATCHET OFF, MUTATE AMT 0 and STRUM TIME 0 — the whole verdict chain now passes every note; only DEVIATE touches the events.
2. Play the loop and raise VEL DEV until the accents breathe — 8–14 is the sweet spot; much beyond ~20 reads as sloppy rather than human.
3. Add TIME DEV 3–8 ms. It only ever adds lateness (that is what keeps the unit zero-latency), so if the part drags, nudge the clip a few milliseconds earlier instead of hoping for pushes.
4. Keep SEED FREE while writing; before printing, lock any number so every bounce reuses exactly the same “player”.

Watch: EV IN must equal EV OUT and EV DROP stays at 0 — if DROP moves, a gate you forgot is still on. The VEL/TIME range bars pulse with every note.

Pitfalls: a locked seed makes every replay identical — when you double-track, give the second take a different seed (or FREE), otherwise both “players” deviate in perfect unison and the double sounds like one. Jitter applies per note-on, so held chords smear slightly — halve TIME DEV for chord material.

2 · Find it, lock it, print it — reproducible variation

Goal: thin a busy loop into a controlled variation that survives bounce and reload bit-identically.

1. Set CHANCE 60–75 and, if you want phrase-level structure, a COND — 2:4 passes only the second bar of every four, FILL/!FILL gate the last two beats of the COND CYCLE.
2. Add MUTATE AMT ~15 on VEL or ALL for occasional flipped verdicts and accents.
3. Lock the seed first: dial any number ≥ 1 (amber LOCKED LED), then step the SEED box +1 per looped pass — every number is a different but perfectly repeatable arrangement.
4. When a pass lands, stop touching SEED: from that moment every replay, freeze and bounce is bit-identical — same drops, same strum shuffles, same mutation hits, same deviate jitter (one shared stream).
5. Print via freeze/render-in-place; the committed take is exactly what you auditioned.

Watch: the PASS/DROP LEDs and the counters — expect EV OUT + EV DROP ≈ EV IN (ratchet bursts inflate EV OUT, see below). If the verdicts do not match your mental picture, the counters tell you which stage is eating notes.

Pitfalls: in FREE mode the drawn seed is never shown — a magic pass you hear while FREE cannot be recovered, so audition locked from the start (or freeze the moment you like it). Editing the clip changes the note stream, so the same seed then yields different decisions. Changing SEED mid-play reseeds instantly — ideal for A/B, but decisions before the edit do not repeat.

3 · Rolls and gates — ratchet meets euclid

Goal: trap-style hi-hat rolls and grid-locked rhythmic gating.

1. Feed a steady 16th-note lane. Set RATCHET DIV to 1/8 or 1/16 — each note is replaced by a burst inside one 16th at the note’s position, so rolls stay tempo-locked at any BPM.
2. Turn RATCHET DEC % negative (−30…−60) for fade-out rolls; positive values build toward the next hit.
3. Layer the gate: EUCLID PULSES 3 / STEPS 8 passes only onsets on the x..x..x. pattern — an instant maximally-even rhythm. ROTATE shifts the hits on or off the beat.
4. Rolls only where they belong: add COND FILL (the last two beats of the cycle’s last bar) and the rest of the loop stays straight.

Watch: the step-LED ring (white marker = current 16th) and Q LOAD — dense bursts fill the 512-slot queue quickly and the bar turns amber past 384. EV OUT counts every burst hit individually, so it legitimately runs far ahead of EV IN.

Pitfalls: a burst always fits inside one 16th regardless of note length — the original note-off is swallowed, so for sustained rolls retrigger the note. EUCLID sits before CHANCE, STRUM and RATCHET in the verdict chain: a note on a dead step never reaches the burst. A strummed chord under ratchet becomes a staircase of mini-rolls (rank × TIME shifts each burst). With transport stopped the pattern advances per note group (~15 ms) rather than along the timeline — judge the real alignment while the loop plays. If a burst ever hangs, a transport jump or CC 123 flushes everything instantly.

13MIDI thru & panic

• Non-note traffic (CC, pitchbend, aftertouch, program change) passes with its original timing — everything travels through one time-sorted queue, so output order is always sample-correct.
• Panic fires on CC 123 (All Notes Off), CC 120 (All Sound Off), a transport jump of more than one bar, switching ENABLED → BYPASS, and on every transport start: queued generated notes are discarded and a note-off is sent for every note still sounding on the output — no hangers, ever. CC and pitchbend already in the queue survive a panic.
• Note-offs are tracked per channel+note: a dropped note's off is swallowed, a passed note's off is delivered (shifted by the same strum/deviate delay as its on), and offs for notes the unit never saw pass straight through.
• Everything stays on the input channel — no MPE splitting, so drum racks and channel-sensitive instruments keep working.

14Automation & parameters

All panel controls are ordinary JSFX parameters — hidden from the generic slider page by design, but fully exposed to REAPER: they appear in the parameter list for envelopes, MIDI/OSC learn, track controls and parameter modulation. Every panel gesture also reports itself as a real parameter change, so touch/latch/write automation recorded from the front panel works exactly like automating the slider.

Parameters 41–45 (PB CMD/ARG/A/B/C) are the test interface of the preset bank (save, load and check slots without the mouse); leave them alone. Parameters 17–39 (and only these besides 41–45; 40 is the colour scheme above) are a diagnostic/test bus used by the automated test harness: the SNT sanity tag, the live counters (EV IN/OUT/DROP, Q LOAD, ACT), a per-note query bus (Q NOTE → Q STATUS/DELAY/VEL), an event log ring buffer (LOG EN/IDX/KIND/M1–M3/T/N) and environment echoes (SRATE, TEMPO, BEATSAMP). Most are read-only outputs the DSP overwrites every block — automating them is pointless, and users can safely ignore them; the interesting ones are mirrored on the front panel anyway.

15Options / Color

Click OPTIONS in the header to open the box. Under COLOR pick one of ten schemes: ACID, CYAN, ORANGE, MAGENTA, YELLOW, RED, BLUE, VIOLET, MINT or ICE. A click on a swatch changes the whole front at once (accent, dimmed accent, panel and ground tint, knob discs); a click outside the box closes it. The choice applies per plug-in instance and is saved with the project and with FX chains (hidden parameter UI Color, parameter 40). The factory colour of TT-LuckyMidiChance is ACID. The LOCKED seed LED and the overloaded Q LOAD bar use the warning colour of the scheme (orange under ACID). Colour has no effect on the MIDI processing.

16Troubleshooting

• Everything passes regardless of settings — the header button is on BYPASS, or the FX sits after the instrument in the chain (it must see the MIDI before the instrument does).
• Different results on every bounce — SEED = 0000 is free-running; lock any number for a reproducible performance.
• EUCLID seems to do nothing — PULSES = 0 bypasses the gate (status reads BYPASS). Set PULSES ≥ 1. If notes drop, check ROTATE: your onsets may land between pulses; notes quantize to the nearest 16th step.
• COND does nothing — it only works while transport plays; stopped, it passes everything by design. Also check that the song position actually reaches the gated bars.
• FILL never triggers — FILL is the last 2 beats of the cycle's last bar; make sure COND CYCLE matches your musical phrase length.
• Strum spreads a chord too far — STRUM TIME is the per-note step, not the total: an n-note chord spreads (n−1) × TIME. Halve it for bigger chords.
• Ratchet notes hang or the queue fills during dense bursts — panic clears automatically on transport jump or ENABLE→off, and a CC 123 always flushes. The Q LOAD bar turns amber above 75 % of the 512-slot queue: shorten bursts or lower the ratchet division.