The intent of these versions of my tools is that people can focus on either the initiator or responder role for their product and leave the other part of the negotiation up to either SendMIDI or ReceiveMIDI. This should make it easier to bootstrap adding MPE Profile support.

https://github.com/gbevin/SendMIDI
https://github.com/gbevin/ReceiveMIDI

SendMIDI allows simulating the role of an MPE Profile initiator, while ReceiveMIDI allows simulating the role of an MPE Profile responder (only on Linux/macOS due to virtual port creation)

Here's an basic example of usage:

Create a virtual MIDI port named profiletest and configure it to support manager channel 1 with 15 member channels as a responder:

receivemidi mpp profiletest 1 15

Use profiletest both as the MIDI output and input port and request the MPE profile to be enabled as an initiator with manager channel 1 and with 6 member channels:

sendmidi dev profiletest mpp profiletest 1 6

The relevant outputs could be:

receivemidi mpp profiletest 1 15
Responder MUID 0x0d1212d6 waiting for MPE Profile negotiation on channel 1
MUID 0x03926473 : MPE Profile enabled with manager channel 1 and 6 member channels
MUID 0x03926473 : MPE Profile details inquired for optional features

sendmidi dev profiletest mpp profiletest 1 6
Initiator MUID 0x03926473 negotating MPE Profile with manager channel 1 and 6 member channels
MUID 0x0d1212d6 : Discovered
MUID 0x0d1212d6 : Requesting MPE Profile enablement with manager channel 1 and 6 member channels
MUID 0x0d1212d6 : MPE Profile enabled with manager channel 1 and 6 member channels
MUID 0x0d1212d6 : Inquiring MPE Profile details for optional features
MUID 0x0d1212d6 : MPE Profile details received for optional features
MUID 0x0d1212d6   channel response : not supported
MUID 0x0d1212d6   pitch bend       : supported
MUID 0x0d1212d6   channel pressure : standard controller
MUID 0x0d1212d6   3rd dimension    : standard controller

This is another possible example:

Create a virtual MIDI port named profiletest and configure it to support any manager channel with up to 8 member channels as a responder, this also disables pitch bend as a supported feature and enables bipolar controllers for channel pressure and 3rd dimension:

receivemidi mpp profiletest 0 8 mpb 0 mcp 2 m3d 2

Use profiletest both as the MIDI output and input port and request the MPE profile to be enabled as an initiator with manager channel 2 and with 10 member channels:

sendmidi dev profiletest mpp profiletest 2 10

Then, use profiletest both as the MIDI output and input port and request the MPE profile to be enabled as an initiator with manager channel 12 and with 6 member channels:

sendmidi dev profiletest mpp profiletest 12 6

The relevant outputs could be:

receivemidi mpp profiletest 0 8 mpb 0 mcp 2 m3d 2
Responder MUID 0x04b33d6f waiting for MPE Profile negotiation on all channels
MUID 0x00166e57 : MPE Profile enabled with manager channel 2 and 8 member channels
MUID 0x00166e57 : MPE Profile details inquired for optional features
MUID 0x001a9680 : MPE Profile disabled with manager channel 2
MUID 0x001a9680 : MPE Profile enabled with manager channel 12 and 4 member channels
MUID 0x001a9680 : MPE Profile details inquired for optional features

sendmidi dev profiletest mpp profiletest 2 10
Initiator MUID 0x00166e57 negotating MPE Profile with manager channel 2 and 10 member channels
MUID 0x04b33d6f : Discovered
MUID 0x04b33d6f : Requesting MPE Profile enablement with manager channel 2 and 10 member channels
MUID 0x04b33d6f : MPE Profile enabled with manager channel 2 and 8 member channels
MUID 0x04b33d6f : Inquiring MPE Profile details for optional features
MUID 0x04b33d6f : MPE Profile details received for optional features
MUID 0x04b33d6f   channel response : not supported
MUID 0x04b33d6f   pitch bend       : not supported
MUID 0x04b33d6f   channel pressure : alternate bipolar controller
MUID 0x04b33d6f   3rd dimension    : alternate bipolar controller

sendmidi dev profiletest mpp profiletest 12 6
Initiator MUID 0x001a9680 negotating MPE Profile with manager channel 12 and 6 member channels
MUID 0x04b33d6f : Discovered
MUID 0x04b33d6f : Requesting MPE Profile enablement with manager channel 12 and 6 member channels
MUID 0x04b33d6f : MPE Profile disabled with manager channel 2
MUID 0x04b33d6f : MPE Profile enabled with manager channel 12 and 4 member channels
MUID 0x04b33d6f : Inquiring MPE Profile details for optional features
MUID 0x04b33d6f : MPE Profile details received for optional features
MUID 0x04b33d6f   channel response : not supported
MUID 0x04b33d6f   pitch bend       : not supported
MUID 0x04b33d6f   channel pressure : alternate bipolar controller
MUID 0x04b33d6f   3rd dimension    : alternate bipolar controller

Full documentation can be found by typing sendmidi -h or receivemidi -h.

Hope this is helpful. Please let me know if you have any feedback.

Get the spec here:
https://midi.org/midi-ci-profile-for-midi-polyphonic-expression

Learn more about the new MIDI 2.0 MPE Profile in this video from NAMM 2024!

https://www.youtube.com/watch?v=rIGYtKF3vfk

• In Per-Split Settings > MIDI Mode, holding ONE CHANNEL now resets all MIDI settings as they are after a Reset command. Similar to holding ChPerNote to quickly change all settings for MPE synths, this is useful for quickly changing all MIDI settings for use with common preset sounds of One Channel synth that are optimized for MIDI piano keyboards:
  Main channel: 1
  Bend Range: +/- 2
  Timbre/Y: CC74
  Loudness/Z: Poly Pressure
• If MIDI Mode is set to ChPerNote and you change either the Bend Range setting or hold ChPerNote to force MPE settings, LinnStrument sends a MIDI RPN 0 “Pitch Bend range” message, which sets the external synth to the same bend range.

Bug fixes

• When using the Arpeggiator to arpeggiate through a held chord and you lifted one finger of the chord, the arpeggio order would reset to the starting note. Fixed.
• When split was on with CC Faders on in one split and Low Row on in the other, sometimes the Low Row lights would turn on on the other split. Fixed.
• When receiving a Bend Range configuration message through MIDI, LinnStrument would echo it back to the MIDI out, which was unnecessary. Fixed.
• When LinnStrument would receive a MIDI Stop command to stop its Step Sequencer, it would unnecessarily echo it back out to the MIDI out. Fixed.

Get it here:
https://www.rogerlinndesign.com/support/support-linnstrument-update-software

https://www.youtube.com/watch?v=SEAp_ffF8EY

It's fascinating to me to see how ubiquitous the term MPE has become now. Several times along the journey, it was almost lost to more marketing-oriented names.

I however always kept putting my foot down in defense of MPE, because I thought that it was exactly as short and nerdy as it needed to be for wide adoption.

http://bit.ly/mpe-spec

Darwin got me to talk about my background, as well as my approach towards musical instrument design and programming in a very friendly chat.

Also available as an audio podcast.
http://artmusictech.libsyn.com/podcast-154-geert-bevin

https://www.youtube.com/watch?v=ZziKiE2Rmx0

https://www.midi.org/midi-articles/the-midi-association-announces-the-v1-1-update-to-the-midi-polyphonic-expression-mpe-specification

https://www.youtube.com/watch?v=-hfzA1M8h48