Since Winter NAMM 2015, I’ve been working on a new MIDI specification together with many other industry professionals (Apple, Bigwig, Haken Audio, KMI, Madrona Labs, Moog Music, Roger Linn Design, ROLI, …). We’ve preliminarily called it Multidimensional Polyphonic Expression, in short: MPE.
The point is very simple: to allow new controllers like the LinnStrument and Eigenharp to have full per-note expressive support in sound generators and DAWs.
We’ve taken a pragmatic approach where we kept the best of what is already in practical use today and structured in so that adding support for MPE would be the least possible effort, while providing the most possible benefit.
A beta version of the spec is available at http://bit.ly/mpe-spec
Feel free to reach out to let us know what you think of it!