MPE vrs PolyAT

Anything about hardware musical instruments.
KVRist
58 posts since 10 Mar, 2009 from Australia

Post Thu Oct 21, 2021 2:45 am

I had always thought of MPE as a bit of a kludge to get around not supporting PolyAT.
Looking for a clear statement of the relative merits.

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KVRAF
20423 posts since 3 Feb, 2005 from in the wilds

Post Thu Oct 21, 2021 6:09 am

MPE is like PolyAT plus a lot more...

KVRist

Topic Starter

58 posts since 10 Mar, 2009 from Australia

Post Thu Oct 21, 2021 1:41 pm

A lot more what though?

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KVRist
482 posts since 1 Jan, 2018

Post Thu Oct 21, 2021 1:54 pm

In addition to per-note pressure, you also get polyphonic pitch bend and an extra per-note expression control (usually corresponding to the front-back motion on an MPE controller).

KVRist

Topic Starter

58 posts since 10 Mar, 2009 from Australia

Post Thu Oct 21, 2021 5:42 pm

So if it’s a piano style keybed then nothing but per note pressure is added/available?

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KVRAF
11376 posts since 26 Jun, 2006 from San Francisco Bay Area

Post Thu Oct 21, 2021 6:36 pm

rACatkvr wrote:
Thu Oct 21, 2021 1:41 pm
A lot more what though?
E
Zerocrossing Media

4th Law of Robotics: When turning evil, display a red indicator light. ~[ ●_● ]~

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KVRAF
11376 posts since 26 Jun, 2006 from San Francisco Bay Area

Post Thu Oct 21, 2021 6:39 pm

rACatkvr wrote:
Thu Oct 21, 2021 5:42 pm
So if it’s a piano style keybed then nothing but per note pressure is added/available?
No.
Zerocrossing Media

4th Law of Robotics: When turning evil, display a red indicator light. ~[ ●_● ]~

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KVRAF
11376 posts since 26 Jun, 2006 from San Francisco Bay Area

Post Thu Oct 21, 2021 6:42 pm

Zerocrossing Media

4th Law of Robotics: When turning evil, display a red indicator light. ~[ ●_● ]~

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KVRAF
20423 posts since 3 Feb, 2005 from in the wilds

Post Thu Oct 21, 2021 6:57 pm

rACatkvr wrote:
Thu Oct 21, 2021 5:42 pm
So if it’s a piano style keybed then nothing but per note pressure is added/available?
Check out Osmose

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KVRist
482 posts since 1 Jan, 2018

Post Thu Oct 21, 2021 7:24 pm

rACatkvr wrote:
Thu Oct 21, 2021 5:42 pm
So if it’s a piano style keybed then nothing but per note pressure is added/available?
If a hardware synth supports MPE but has a piano style keyboard, yes, you will only get the benefits of pressure per note using that keyboard. However, you would still get the MPE functionality via MIDI with an MPE controller.

KVRist

Topic Starter

58 posts since 10 Mar, 2009 from Australia

Post Fri Oct 22, 2021 4:35 am

Thanks for the clear explanation.

KVRAF
5478 posts since 23 Mar, 2006 from pendeLondonmonium

Post Fri Oct 22, 2021 7:13 am

rACatkvr wrote:
Thu Oct 21, 2021 1:41 pm
A lot more what though?
Contiunous-pressure.

Polyphonic pressure as seen in most of the keyboard designs relies on the standard 'aftertouch' mechanism. However, in most MPE controllers/instruments pressure is implemenetd as a continuous mechanism. This is a huge difference. What it means in practice is that with continuous-pressure we can now imitate natural sounds created by bowing or breath. In order to obtain a smooth response, a smooth articulation of volume/timbre, as heard when bowing a string or blowing air into a reed, we need this continuous pressure, simply becouse a bow gesture, or a breath is continuous. We start with a soft, gentle bow, and then apply pressure to get more volume and tone. Same with the breath, start blowing gently into the reed mouthpiece and then increase the force to obtain more volume/tone. This can be mimiced exactly with continous pressure as seen in most MPE instruments.

Here is an example of a sound that uses continuous-pressure to mimic breath:

https://soundcloud.com/electric-himalay ... rsian-reed

And what makes that sound special is that I'm playing a drone in the left hand, and solo in the right - this is the polyphonic pressure aspect, but now, I am free to articulate the volume/tone with continuous pressure without having to do it with the mod-wheel (I couldn't do it any way since I'm using two hands, and to use the mod-wheel here, I'd need another hand, and besides, the mod-wheel would apply to all the notes played). So for me at least, this is huge: polyphonic pressure, and continuous control thereof. That sound could not be exectued/played on a normal midi keyboard with normal poly-aftertouch.
http://www.electric-himalaya.com
VSTi and hardware synth sound design
3D/5D sound design since 2012

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