How to Produce Microtonally Using MPE MIDI

Published: January 12, 2024 • Category: Production • Reading time: 12 minutes

MPE (MIDI Polyphonic Expression) revolutionizes microtonal music production by allowing individual control over each note's pitch, pressure, and timbre. This technology finally makes it practical to produce complex microtonal compositions with the same ease and expressiveness as traditional 12-tone music.

Understanding MPE Technology

Traditional MIDI treats all notes as part of a single voice, meaning pitch bend affects every note simultaneously. MPE solves this by assigning each note its own MIDI channel, enabling independent control of pitch bend, pressure, and modulation for every individual note.

Key MPE Parameters

Pitch Bend (X-axis): Individual pitch control for each note
Pressure (Z-axis): Aftertouch sensitivity per note
Timbre (Y-axis): Often mapped to filter cutoff or harmonic content
Release Velocity: How quickly you release each key

Essential MPE Controllers for Microtonal Work

Several controllers excel at microtonal expression with MPE:

Roli Seaboard

The soft silicone surface allows smooth pitch bending between notes, making it ideal for microtonal glides and expressive pitch adjustments. The five-dimensional touch sensitivity enables nuanced control over tuning and expression.

Linnstrument

This grid controller offers precise control with its pressure-sensitive pads arranged in a layout that makes microtonal intervals visually logical. Each pad can be tuned to any pitch, making custom tuning systems straightforward.

Continuum Fingerboard

Perhaps the ultimate microtonal controller, the Continuum offers continuous pitch control across its entire surface. Every position can be mapped to any frequency, enabling perfect just intonation and exotic tuning systems.

Sensel Morph

With interchangeable overlays and high-resolution pressure sensing, the Morph adapts to various microtonal workflows while maintaining precise MPE control.

Software Setup for Microtonal MPE

Configuring your DAW and instruments for microtonal MPE requires specific setup procedures:

MPE Configuration

Most MPE controllers need to be set to MPE mode, which typically involves:

Setting the controller to MPE mode (usually in device settings)
Choosing the number of MPE channels (typically 15 for Zone 1)
Setting pitch bend range (often 24 or 48 semitones for microtonal work)
Configuring pressure and timbre mapping

DAW Configuration

Major DAWs handle MPE differently:

Ableton Live

Enable MPE in Preferences → Link/Tempo/MIDI → MPE. Use Wavetable, Bass, or Operator with MPE-capable devices. The Max for Live "MPE Control" device helps map MPE data to any parameter.

Logic Pro

Enable MPE in Track Settings → Input → MPE Mode. Use Sculpture, Alchemy, or Sampler instruments. Logic's built-in tuning tables support various microtonal scales.

Reaper

Highly flexible MPE support through JS plugins and custom scripting. Excellent for complex microtonal routing and processing.

MPE-Capable Instruments for Microtonal Work

Choose instruments that support both MPE and custom tuning:

Hardware Synthesizers

Moog One: Full MPE support with microtuning capabilities
Sequential Prophet X: MPE with custom tuning tables
Hydrasynth: Excellent MPE implementation with poly aftertouch

Software Instruments

Pianoteq: Physical modeling piano with extensive tuning options
U-he Zebra/Diva: Comprehensive microtuning support
Native Instruments Reaktor: Build custom microtonal instruments
Surge XT: Free synth with excellent microtonal capabilities

Tuning Systems and Implementation

MPE makes various tuning systems accessible through different approaches:

Scala File Integration

Many instruments support Scala (.scl) tuning files. Create or download tuning files from the Scala archive:

Just intonation scales
Historical temperaments
Non-Western tuning systems
Experimental microtonal scales

Real-Time Pitch Mapping

Use MPE pitch bend to access microtonal intervals in real-time. Map controller zones to specific pitch ranges, allowing intuitive access to quarter-tones, just intonation ratios, or completely custom tunings.

Dynamic Tuning

Advanced setups can change tuning systems dynamically during performance, switching between temperaments based on harmonic context or artistic intent.

Practical Production Techniques

Effective microtonal MPE production requires specific approaches:

Recording Strategies

Record MPE data, not just audio. This preserves all expression data for later editing and allows you to change sounds while maintaining microtonal performance nuances.

Editing MPE Data

Most DAWs allow detailed editing of MPE parameters:

Adjust pitch bend curves for smoother microtonal transitions
Modify pressure data to enhance expressiveness
Quantize timing while preserving pitch and expression data
Layer multiple MPE tracks with different tuning systems

Mixing Microtonal Elements

Microtonal music may require different mixing approaches:

Use harmonic-aware EQ to enhance natural overtone relationships
Apply chorus and delay effects carefully to avoid masking delicate tuning
Consider stereo placement based on pitch relationships

Building Custom Microtonal Instruments

Advanced users can create specialized microtonal MPE instruments:

Max/MSP Development

Build custom instruments with precise microtonal control and unique MPE mappings. Max's extensive microtonal objects make complex tuning systems manageable.

Pure Data

Free alternative to Max for creating custom microtonal instruments. Excellent for experimental tuning system research.

Reaktor Ensembles

Native Instruments Reaktor allows complex instrument design with full MPE and microtuning support.

Workflow Optimization

Streamline your microtonal MPE workflow with these strategies:

Template Creation

Build project templates with pre-configured MPE tracks, tuning systems, and routing. Include your most-used microtonal instruments with appropriate settings.

Controller Mapping

Create custom controller mappings for quick access to different tuning systems and microtonal scales during performance and composition.

Reference Tracks

Maintain reference tracks with pure intervals and tuning drones to help maintain pitch accuracy during composition.

Collaborative Workflows

Working with other musicians on microtonal MPE projects requires coordination:

Tuning Documentation

Document your tuning systems clearly, including Scala files, pitch mappings, and any custom controller configurations.

Stem Preparation

When sharing stems, include both the raw MPE data and rendered audio to preserve editing flexibility while ensuring compatibility.

Live Performance Setup

For live performance, create redundant backup systems and ensure all musicians understand the microtonal mappings being used.

Troubleshooting Common Issues

Address typical microtonal MPE production challenges:

Latency Issues

High-resolution pitch bend can increase CPU load. Optimize buffer sizes and consider freezing tracks when not actively editing MPE data.

Tuning Drift

Monitor tuning accuracy during long sessions. Some controllers may drift slightly over time, requiring occasional recalibration.

Software Compatibility

Not all plugins handle MPE data correctly. Test your signal chain thoroughly and have backup routing options ready.

"MPE transforms microtonal music from a theoretical exercise into an expressive, playable reality."

MPE technology democratizes microtonal music production, making complex tuning systems as accessible as traditional scales. With the right controller, software, and techniques, you can explore the vast landscape of microtonal expression with unprecedented ease and musicality.

Start with simple microtonal experiments, gradually building complexity as you become comfortable with MPE workflows. The combination of expressive control and precise tuning opens entirely new musical territories waiting to be explored.