P33

Objectives

By the end of this chapter you will be able to:

  • Explain what a parameter lock (plock) is and why it matters.
  • Set a parameter lock on a single step.
  • Use parameter locks to vary patterns without writing new ones.
  • Recognise parameter locks in popular music.

What is a parameter lock?

A parameter lock (often abbreviated plock) is a setting that overrides the default value of a parameter on a single step. For example:

  • Step 1: kick at velocity 100. Step 5: kick at velocity 120 (the plock). Step 9: kick at velocity 80.
  • Step 1: snare with no FX. Step 9: snare with bitcrush.

Parameter locks are how producers add variation to a beat without rewriting the whole pattern. J Dilla’s beats are full of them — a slightly louder kick here, a slightly different snare there.

Sidebar — Allen on parameter locks. Allen (Music Theory for Electronic Music Producers) calls parameter locks the “secret weapon” of the piano roll. They allow you to introduce micro-variations that keep a beat interesting over time. Without them, a 4-bar loop sounds robotic. With them, it sounds alive.

How to set a parameter lock on the PO-33

The PO-33 supports parameter locks via Knob A and Knob B in WRITE mode:

  1. Press WRITE, PLAY.
  2. Wait for the step you want to lock.
  3. Hold the pad for that slot (e.g., pad 9 for kick).
  4. While holding, turn Knob A (sets velocity, 0–127).
  5. While holding, turn Knob B (sets pitch, ±12 semitones).
  6. Release the pad.

The plock is now set. When the pattern plays, that step will use the locked values.

Sidebar — firmware support. The Ravine: Phoenix firmware implements parameter locks for velocity and pitch. The real PO-33 also supports FX plocks (apply an FX to one step). We will add FX plocks in a future firmware version.

An example: a velocity-ramped kick

A classic drum programming technique is the velocity ramp — the kick gets louder as the beat progresses, then drops back. To ramp the kick from velocity 80 to 120 over 8 steps:

  1. Step 1: kick velocity 80.
  2. Step 5: kick velocity 100.
  3. Step 9: kick velocity 120.
  4. Step 13: kick velocity 100.

The kick swells through the loop. This is a parameter lock on every step.

An example: a pitch-shifted snare

A classic dub technique is to pitch the snare down by a few semitones on certain steps. To pitch-shift the snare down 3 semitones on step 13:

  1. Press WRITE, PLAY.
  2. Wait for step 13.
  3. Hold pad 10 (snare).
  4. Turn Knob B down by 3 (the screen shows -3 semitones).
  5. Release pad 10.

The snare on step 13 will play 3 semitones lower than the snare on step 5. The result is a “wobble” — the snare sounds like it’s bouncing.

Using parameter locks to vary patterns

Parameter locks let you create variation without writing new patterns. Consider this trick:

  • Pattern 1: kick on steps 1, 5, 9, 13 at velocity 100.
  • Pattern 2: same kick pattern, but velocity 120 on step 5 and velocity 80 on step 13 (via plocks).

Patterns 1 and 2 sound almost identical, but the second has subtle dynamic variation. Chain them together and the kick will swell and dip across the chain.

Guided exercise: a kick with parameter locks

Success criteria: a kick pattern with velocity 80 on step 1, velocity 100 on step 5, velocity 120 on step 9, velocity 100 on step 13.

  1. Erase the pattern.
  2. Press WRITE, PLAY.
  3. Step 1: hold pad 9. Turn Knob A until screen shows “80”. Release pad 9.
  4. Step 5: hold pad 9. Turn Knob A until screen shows “100”. Release pad 9.
  5. Step 9: hold pad 9. Turn Knob A until screen shows “120”. Release pad 9.
  6. Step 13: hold pad 9. Turn Knob A until screen shows “100”. Release pad 9.
  7. Press WRITE to exit.

Play the pattern. The kick should swell across the loop. This is a “humanised” kick — it sounds like a real drummer hitting harder on the downbeats.

Creative challenge: a pitched snare roll

Pitch-shift the snare down 2 semitones on every odd step (1, 3, 5, 7, …). The result is a “wobble snare” that sounds like the snare is bouncing.

  1. Press WRITE, PLAY.
  2. Step 1: hold pad 10. Turn Knob B down by 2. Release.
  3. Step 5: hold pad 10. Turn Knob B down by 2. Release.
  4. Step 9: hold pad 10. Turn Knob B down by 2. Release.
  5. Step 13: hold pad 10. Turn Knob B down by 2. Release.

Now play the beat. It should sound “underwater” — the snare is pitched below the rest of the drums.

Listening assignment

Listen to:

  • J Dilla, “Workinonit” (2006). The kick has subtle velocity variation on every step. Listen for the “swell” of the kick — it’s slightly louder on some beats, quieter on others. This is parameter locks.
  • Aphex Twin, “Windowlicker” (1999). The drums have pitch-shifted elements — the snare drops and rises across the track. Listen for the “wobble” on certain snare hits.
  • Burial, “Archangel” (2007). The vocal sample has velocity variation on every step. Some syllables are louder, some quieter. This is what makes the vocal feel “human”.
  • Autechre, “Gantz Graf” (2002). Extreme parameter locks. Every step has a different setting. The result is “robotic” and “human” at the same time.

Summary and checkpoint

Key takeaways:

  • A parameter lock overrides the default value of a parameter on a single step.
  • The PO-33 supports velocity and pitch plocks.
  • Plocks add variation to a beat without rewriting the pattern.
  • Plocks are how producers make beats sound “human”.

Self-check:

  • [ ] Can you set a velocity plock on a kick?
  • [ ] Can you set a pitch plock on a snare?
  • [ ] Can you create a velocity-ramped kick?
  • [ ] Do you understand why J Dilla’s beats feel “alive”?

If you answered “yes” to all four, move on to Chapter 17.