The MIDI Manufacturers Association (MMA) has formally ratified the MIDI Polyphonic Expression (MPE) enhancement to the MIDI Specification. MPE enables electronic instruments such as synthesizers to provide a level of expressiveness typically possible only with acoustic instruments.

Prior to MPE, expressive gestures on synthesizers—such as pitch bending or adding
vibrato—affected all notes being played. With MPE, every note a musician plays can be articulated individually for much greater expressiveness.

In MPE, each note is assigned its own MIDI Channel, so that Channel-wide expression messages can be applied to each note individually. Music making products (such as the ROLI Seaboard, Moog's Animoog, Roger Linn's Linnstrument, and Apple's Logic) take advantage of this so that musicians can apply multiple dimensions of finger movement control: left and right, forward and back, downward pressure, and more.

MMA President Tom White notes that "The efforts of the members (companies) of MMA has resulted in a specification for Polyphonic Expression that provides for interoperability among products from different manufacturers, and benefits the entire music industry."

Jean-Baptiste Thiebaut of ROLI concurs. "The MPE specification paves the way for a new generation of expressive controllers and music software, providing many creative opportunities for live musicians and producers. MPE remains fully compatible with MIDI."

Another developer of MPE hardware Roger Linn says: "It's nice to see the MMA formalize MPE and add a few useful details. The standardization will help to broaden this category."

The MPE specification will be available for download in the coming weeks. To obtain a free copy, join the MIDI Association, the global community of people who work, play and create with MIDI.