Most introductions to MIDI Polyphonic Expression list the same three gestures: pitch bend, pressure, and a third "slide" axis. But if you read how controller makers describe their instruments, you will find a fifth dimension that rarely gets a mention in synth manuals: Lift, the speed and manner in which you release a note.
The five dimensions, briefly
The vocabulary comes from the MPE community and from controller makers such as Roger Linn Design and ROLI. The five dimensions are Strike (how hard you start a note), Press (pressure while it sounds), Glide (horizontal pitch movement), Slide (vertical position, typically sent as CC74) and Lift (how quickly you release).
Four of those map neatly onto messages most synths already understand: note-on velocity, per-channel pressure, pitch bend and CC74. Lift is the odd one out because it relies on note-off velocity, a part of the MIDI specification that most keyboards never sent and most instruments ignored for decades.
Why release velocity matters
On an acoustic instrument the end of a note is part of its character. A bowed string that is lifted gently fades; a plucked string that is damped sharply stops dead; a piano key released quickly triggers a different damper noise than one eased up. Without a release gesture, every note ends the same way, and a lot of the realism you gained from per-note pressure is lost in the final fraction of a second.
With release velocity, a patch can do things like shorten or lengthen the release envelope, add a key-up sample, change a reverb tail, or trigger a final pitch fall. These are small details, but they are exactly the kind of detail that separates a played phrase from a sequenced one.
Who actually sends it
Support on the controller side is better than many players assume. Expressive E's Osmose is built around a mechanical keybed with sensing on both the strike and the release, and the Osmose documentation presents release as one of its expressive gestures. The LinnStrument can send release velocity as an optional feature that you enable in its settings. Many other MPE devices expose release data in some form, but behaviour varies by model and firmware, so check your controller's manual before building a workflow around it.
On the software side, the situation is more mixed. Some synths read note-off velocity and map it to a modulation source; others quietly discard it. If a plugin lists "release velocity" or "note-off velocity" in its modulation matrix, it is usually a good sign that its designers thought about this.
Working around gaps
If your controller does not send release velocity, or your synth ignores it, you still have options. The free MPE Emulator plugin by Attila M. Magyar, for example, can override note release velocity with trigger velocity, which gives you a predictable, playable release behaviour from an ordinary keyboard. It is a blunt tool compared with a real release gesture, but it shows that the parameter is worth caring about.
Inside your DAW, check how note-off velocity is recorded. Some hosts store it with the note and let you edit it in the piano roll; others do not display it at all. Before committing to a long performance take, record a short test, open the editor and verify that the release values survived.
Practical ways to use Lift
A few starting points when you want to explore it:
- Map release velocity to release time so that quick lifts give staccato endings and slow lifts produce long, singing tails.
- Use it on percussive patches to control how much a note is damped, much like choking a cymbal or palm-muting a string.
- Trigger a release layer such as a breath, a bow lift or a key noise, scaled by how fast you let go.
- Keep it subtle. The value of Lift is realism, not spectacle, so small ranges usually sound better than extreme settings.
The takeaway
MPE is often sold on dramatic gestures such as wide glides and heavy pressure swells. Lift is quieter, but it completes the picture: every note has a beginning, a middle and an end, and expressive control over all three is what makes a performance feel alive. If you own a controller that sends release data, spend an afternoon mapping it. You may find that the most natural-sounding improvement to your playing is the one you were not looking for.