July 26, 2020
New controller, same protocol - MPE regenerates MIDI
MIDI - The end of an era?
The domination of the "Musical Instrument Digital Interface" began with its introduction in the early 1980s as a standard communication protocol for transmitting note, modulation and control data. The initiative was started by a group of leading manufacturers of digital and analog musical instruments who wanted to make their devices easier to control. The growth in the number of products available had increased the demand for compatible interfaces, and now customers would no longer need to deal with the unmanageable quantity of individual solutions on the market.
To ensure 100% compatibility, MIDI has not undergone any major updates or upgrades since 1983. Meanwhile, the amount of data the protocol needs to transmit has continued to grow without pause. The time had come to find a way to reform MIDI without undoing its basic functionality.
MPE - The start of an era?
By dividing the transmission of control data into 16 virtual channels, MIDI made it possible to play a range of devices and program banks simultaneously using a single connection. It was on this foundation that producers began using the DAW as a central sequencer for synthesizers with complicated cable setups. But with the growing popularity of computer-based virtual instruments, elaborate cabled connections were not longer absolutely necessary.
As a result, interest in pure controllers in particular began to grow, which provided a tactile control experience while using software to generate sound. Initially, these controllers could only be used with physical MIDI ports, but more and more frequently these ports were being supplemented or replaced with USB. It was at this point, if not before, that people began to ask why a digital, higher-bandwidth connection should be constricted to suit the limitations of a protocol from 1983. The answer to the resulting dilemma between compatibility and limited functionality came in the form of MIDI Polyphonic Expression, or MPE for short.
How does MPE work?
MPE assigns each note to its own channel, so modulations for individual notes are transmitted separately. Classic MIDI sends controller data, such as pitch bend, over a single channel. This means that each note being played on that channel is modulated in the same manner. But with MPE, MIDI channels are broken down into subsections, or zones, allowing multiple polyphonic instruments to be played in parallel and clearing the way for creative techniques.
Modern controllers like the ROLI Seaboard allow players to control the sound with their fingers across multiple touch dimensions, including applying pressure left and right, forward and backward, and up and down. MPE converts these gestures into sound parameters such as pitch bend, aftertouch, vibrato and other freely-selectable parameters and sends them along to the right instruments.
In addition to countless experimental and novel sounds, the Seaboard also makes it possible to apply authentic-sounding modulations which behave like acoustic instruments. Getting a violin to sing or playing a powerful guitar solo is still a matter of technique, but this sound is no longer limited to strings.
Plug in, rock out
MPE integrates the use of advanced controllers while remaining compatible with the MIDI standard.
DAWs like Samplitude Pro X explicitly support MPE, but they use normal MIDI tracks. All of the normal editing features are still available, but now they can be applied to individual notes.
Expressive playing is in no way a niche of cutting-edge electronic music. MPE is a perfect go-to technology for producers looking to make use of sample packs and emulations instead of playing and recording instruments, whether as a stylistic choice or simply to save time.