request: support Multidimensional Polyphonic Expression (MPE)

[wolftune]

I don't know the exact spec, but the main idea is that each note gets routed to a different MIDI channel so that expressiveness of all sorts can be achieved on a per-note basis. Controllers like the Linnstrument do this. Helm already works this way (or similar) for pitch-bend, it seems it could be updated to the full MPE spec…

[hammerandtongs]

I'd love to see this.

A Roli Seaboard or Keith Mcmillen Seaboard Pro 4(not out yet) is on my shortlist but it needs a sweet opensource synth to go with it :)

[hammerandtongs]

Quick onramp https://factotumo.com/2015/09/midi-mpe-explanation-by-spec-author-geert-bevin/

[mtytel]

Any example of an existing synth that supports MPE?
Wondering if there's a standard. Is it just like a second and third aftertouch? Or is it more complicated than that?

[wolftune]

The two main resources I know about: https://www.midi.org/articles/midi-polyphonic-expression-mpe and http://expressiveness.org/

The first lists existing synths. The standard seems not totally finalized. Yes, it's like extra aftertouches, but polyphonic and something about effectively giving each note it's own channel where it can have per note CC's of anything. I'm not fully clear on it all.

[hammerandtongs]

I encourage you guys to watch this https://factotumo.com/2015/09/midi-mpe-explanation-by-spec-author-geert-bevin/ I linked above.

It's 8 minutes long and he shows a midi trace as he is using a linnstrument, he is also the spec author.

Each note down sends on a new channel so that the mod wheel and pitch wheel are modulateable per note. Channel 1(0) is left for common midi commands.

I'm currently using it via a hardware synth on a $300 Roli Seaboard Block and loving it. It really is like a new instrument so starting with the cheaper Block before you decide is a good way to go.

[MrBollie]

Hello there,

seems like helm perfectly receives midi data from all channels, however, in MPE mode, when I bend a note, that seems to result in a global pitchbend and not for that note being transferred over the channel that note has been transfered in.

I set Voices to 16 and Pitchbend to 48 semitones, so it matches with my Seaboard settings.

Regards
Bollie

[wolftune]

oops, clicked the wrong button (accidentally closed this).

I didn't know that Helm had an MPE mode yet. Last I checked, it did separate the pitch-bend specifically on different channels, which is the one element needed for certain microtonal inputs that are older than MPE. Clearly, that should be the same with MPE also, just still more elements become channel-specific as well.

[MrBollie]

Ah, thanks for your reply. :) Yes, that explains it! Without having looked at the source code, helm looks rather juce'y and JUCE has a designated MPE module, if that's of any help. :)

https://juce.com/doc/group__juce__audio__basics-mpe

[wolftune]

Well, probably the answer is to wait for the full MIDI 2.0 spec and support that. That seems the real future (and quite musically exciting)