SAMPLED

Gear, instruments and tools · updated 2026-08-16

AFTERTOUCH

Pressure applied after a key is already down, sent as extra modulation. Channel aftertouch applies to the whole keyboard; polyphonic aftertouch is per note.

Top-down photograph of an Akai MPC Live standalone sampler showing its sixteen velocity-sensitive pads, touchscreen browser and Q-Link knobs — the hardware sampler workflow these gear terms describe.
Gear, instruments and tools — Top-down photograph of an Akai MPC Live standalone sampler showing its sixteen velocity-sensitive pads, touchscreen browser and Q-Link knobs — the hardware sampler workflow these gear terms describe.

Photo: Akai MPC Live (2017) (opens in a new tab) by Joan Recordà (opens in a new tab), via Wikimedia Commons — CC BY-SA 4.0 (opens in a new tab)

Key takeaways

  • Pressure applied after a key is already down, sent as extra modulation.
  • Channel aftertouch applies to the whole keyboard; polyphonic aftertouch is per note.
  • Channel aftertouch reports one pressure value for the whole keyboard; polyphonic aftertouch reports it per note and is rare and expensive.
  • Map channel aftertouch to filter cutoff or vibrato depth so leaning into a note opens the sound without touching a wheel.
  • Watch out: leaving aftertouch recording enabled by default.

Quick checklist

  • Can you define aftertouch in one sentence without looking?
  • Can you point at aftertouch in a real session, mix or contract?
  • Have you tried the practical move above at least once?
  • Would you catch the common mistake before it costs you a take?
  • Have you opened one of the primary sources below rather than a forum thread?

AFTERTOUCH IN DEPTH

Aftertouch is pressure sent after a key is already held down, used as an extra modulation source. Channel aftertouch reports one pressure value for the whole keyboard; polyphonic aftertouch reports it per note and is rare and expensive. It is a performance feature, not a recording feature, and it can flood a MIDI stream with data.

How it works in practice

Map channel aftertouch to filter cutoff or vibrato depth so leaning into a note opens the sound without touching a wheel.

The mistake people make

Leaving aftertouch recording enabled by default. Unmapped pressure data bloats MIDI clips and can retrigger parameters unexpectedly on other instruments.

WHERE AFTERTOUCH SITS

Aftertouch belongs to gear, instruments and tools in the Sampled music glossary. The boxes, controllers and sample formats a producer is expected to know by name — from the MPC to a one-shot.

TEST YOURSELF

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3 quick questions on aftertouch. Answers are marked instantly — nothing is sent anywhere.

  1. 1. Which statement best describes aftertouch?

  2. 2. What is the mistake people most often make with aftertouch?

  3. 3. In practice, which of these applies to aftertouch?

Ready for the full thing? Take the 25-question terminology test and get a certificate with your name and score.

SOURCES AND CITATIONS

Free, primary references for aftertouch — standards bodies, manufacturers, government offices and university course material. Each one lists the line of this entry it backs up.

  • MIDI Association — MIDI messages (opens in a new tab)

    Specification owner · The MIDI Association

    “Pressure applied after a key is already down, sent as extra modulation.”— the claim this source supports

    Why it counts: The body that publishes the MIDI specification, so this is the definition hardware and software are built against.

  • MIDI Association — MPE specification (opens in a new tab)

    Specification owner · The MIDI Association

    “Channel aftertouch applies to the whole keyboard; polyphonic aftertouch is per note.”— the claim this source supports

    Why it counts: The body that publishes the MIDI specification, so this is the definition hardware and software are built against.

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