MiIDI has has the ability to send notes and controllers on separate channels since day 1. Does MPE add anything in terms of the spec?
MPE generally global settings on channel 1, then Notes on channel 2,3,4,5…,( each note and pitch bend messages on a separate channel) CC74 for expressive … find more at the end of this page: https://support.roli.com/support/solutions/articles/36000027933-what-is-mpe-
Yeah, I know, but that’s been a recommendation in midi for a long time. I introduced it and got it passed in 1986.
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The differences between MPE and Mono Mode, from the MPE specification:
The specification describes a recommended way of using individual MIDI Channels to achieve per-note control without requiring Mono Mode (which would restrict polyphony to a maximum of 16 notes). This enables richer communication between increasingly expressive MIDI hardware and software.
MPE achieves per-note control in a way that is similar to MIDI Mode 4 (“Mono Mode”):
• Wherever possible, every sounding note is assigned its own MIDI Channel for the lifetime of that note. This allows Control Change and Pitch Bend messages to be addressed uniquely to that note.
• A Registered Parameter Number is used to set the range of Channels over which notes are sent and received. The MIDI Channel space can be divided into sub-spaces called Zones, so that multi-timbral playing is still possible using only one MIDI cable.
• Each Zone has a dedicated extra Channel, called the Master Channel, which conveys information common to all notes in that Zone, including pedal data and overall Pitch Bend.
However, MPE addresses the need for higher polyphony by operating in MIDI Mode 3 (“Poly Mode”) where every Channel can be polyphonic. If the number of active notes exceeds the number of available Channels, two or more notes will have to share a Channel. Any notes that share a Channel will not be uniquely controllable, but this can be preferable to limiting polyphony by preventing a new note from sounding, or stopping an older note.
MPE also defines these additional behaviors for senders and receivers:
• Pitch Bend is, by default, set to a range of ±48 semitones for per-note bend and ±2 semitones for Master bend. Either range may be changed to a number of semitones between 0 and ±96 using RPN 0.
• Aftertouch is sent using the Channel Pressure message. To preserve compatibility with existing MIDI devices, Polyphonic Key Pressure may be used with notes on the Master Channel, but not on other Channels.
• In addition to being able to express per-note pitch (Pitch Bend) and pressure (Channel Pressure), a third dimension of per-note control may be expressed using MIDI CC #74.