Session 15: Conditional Trigs & Fill Mode

Objective: Make patterns generative using conditional trigs. Set steps to fire on a 50% chance, every other loop, only after a previous trig played, only during fills. Build a pattern that evolves over 32 loops without ever repeating identically.

Warm-Up (2 min)

You can build patterns. They loop perfectly. After 8 bars, they get boring. Conditional trigs solve that. Press [PLAY] on a current pattern, listen for 16 bars, notice how repetition deadens. Stop. Time to add evolution.

Setup

Start from the LAB project. Have a working pattern on Tracks 1-3 (drums minimum). Trigs placed in standard positions. Press [PLAY] to confirm — note how the pattern feels static. We're about to break that.

Exercises

Exercise 1: Probability — The 50% Trick (4 min)

The simplest conditional: a step that fires randomly with a probability.

1. Press [STOP]. Press [TRACK 3] (your hat track, with trigs on 3, 7, 11, 15)
2. Hold [TRIG 3]. Find the TRIG CONDITION parameter (often on the screen as you hold; or press an arrow key to navigate options)
3. Set TRG (trig condition) to 50%. Release
4. Hold [TRIG 7] + TRG = 50%. Release. Repeat for trigs 11 and 15
5. Press [PLAY]. The hats now play roughly half as often, randomly. Each loop sounds different
6. Other probabilities: 25%, 33%, 50%, 66%, 75%. Choose based on density desired

Exercise 2: 1:N — Every Nth Loop (4 min)

Trig fires only on every Nth iteration of the pattern.

1. Stop. Press [TRACK 2] (snare). Hold [TRIG 13] (a snare trig)
2. Set TRG to 1:2 — fires only on every 2nd loop
3. Now hold [TRIG 5] (also snare) + TRG = 2:2 — fires only on the other loop
4. Press [PLAY]. Loop 1: snare on step 13. Loop 2: snare on step 5. Loop 3: step 13. Loop 4: step 5
5. Other ratios: 1:2, 2:2, 1:3, 2:3, 3:3, 1:4, 2:4, etc. — patterns that morph over multi-loop cycles
6. Try TRG = 1:4 on a kick — kicks only the first of every 4 loops. Adds a low-frequency pulse to long-form patterns

Exercise 3: PRE — Conditional on Previous Trig (3 min)

PRE means "fire this trig only if the previous conditional trig fired." Cascading conditional logic.

1. Stop. Press [TRACK 1] (kick). Place trigs on 1, 5, 9, 13
2. Hold [TRIG 5] + TRG = 50%
3. Hold [TRIG 9] + TRG = PRE (only fires if step 5 fired)
4. Hold [TRIG 13] + TRG = PRE (only fires if step 9 fired, which only fires if 5 fired)
5. Press [PLAY]. Either: only step 1 fires (50% chance every loop), OR steps 1 + 5 + 9 + 13 all fire (the other 50%). All-or-nothing chains
6. NOT-PRE (!PRE in some firmware): the inverse — fires only if previous did NOT fire

Exercise 4: FILL — Fill Mode Trigs (4 min)

Some trigs fire only when you press the FILL button. Used for drum fills and break sections.

1. Stop. Press [TRACK 2] (snare). Place trigs on [TRIG 14, 15, 16] — three rapid snare hits at the end of the bar
2. Hold each of those trigs and set TRG = FILL — only plays during fill mode
3. Press [PLAY]. Normal pattern plays — those three end-of-bar snares are silent
4. Press [FUNC] + [YES] (FILL key, varies by firmware) — fill mode toggles on. Keep playing. The next bar's last 3 steps have the snare fill
5. Release fill mode (toggle off, or hold-only). Pattern returns to normal
6. Use case: build entire fill sections that are silent until you trigger them — instant break, drop, transition material

Exercise 5: Combine Conditional Types (5 min)

Layer the conditional types for evolving patterns.

1. Track 1 (kick): trigs on 1, 5, 9, 13
   • Step 1: TRG = 1:1 (always fires — root anchor)
   • Step 5: TRG = 75%
   • Step 9: TRG = 1:2 (every other loop)
   • Step 13: TRG = PRE (fires if 9 fired)
2. Track 2 (snare): trigs on 5, 13
   • Step 5: TRG = 1:2
   • Step 13: TRG = 2:2 (the loop where 5 doesn't)
3. Track 3 (hat): trigs on 3, 7, 11, 15
   • Steps 3, 11: TRG = 50%
   • Steps 7, 15: TRG = 66%
4. Press [PLAY] and let it run for 32 bars. Listen — the pattern morphs continuously. Sometimes sparse, sometimes dense. Snares alternate. Kicks have probabilistic anchors
5. Record a 30-second pass to capture one variation: press [FUNC] + [REC1] (or set up a track recorder) to capture the audio
6. Save: [FUNC] + [PROJ]

Exploration (if time allows)

• Try NEI (neighbor) condition — fires if the same step on the neighboring track fired. Useful for sympathetic patterns
• Combine 1:N with PRE for deeply staggered patterns: trig 1 = 1:4, trig 2 = PRE — both fire only on every 4th loop
• Long patterns + conditional trigs = music that feels composed rather than looped. 64-step patterns with conditional trigs can sustain interest for minutes

Output Checklist

• I set a trig to 50% and heard probabilistic firing
• I used 1:N to make a trig fire only on certain loops
• I chained PRE conditional trigs
• I built fill-mode-only trigs and triggered them with the FILL gesture
• I built a multi-track pattern combining 4+ different conditional types
• I let the pattern play for 16+ bars and heard it evolve

Key Takeaways

• Conditional trigs turn static patterns into generative ones — 50%, 1:N, PRE, FILL, NEI are the vocabulary
• Probability (50%, etc.) = randomness; 1:N = deterministic cycling; PRE = chained logic; FILL = on-demand sections
• A pattern with mixed conditional types can play for 32+ bars without repeating identically — solves the boredom problem
• Combine with parameter locks (Session 14) for evolution that's both rhythmic AND timbral

Next Session Preview

Next: micro timing, slide trigs, and scale settings. Shift trigs off the grid by fractions of a step (humanization). Slide parameters smoothly between steps. Set per-track length for polymetric patterns. The advanced sequencer toolkit.