MPE Emulator is a powerful MIDI plugin designed to transform standard MIDI signals into MIDI Polyphonic Expression (MPE) data by applying user-defined mappings and rules. Acting as a MIDI proxy, it selectively converts single-channel messages such as Aftertouch, Pitch Bend, and other MIDI Control Changes into polyphonic expressions. Users can target these effects to specific notes based on criteria like lowest, highest, oldest, or newest notes, either across the entire keyboard or within a customizable split range. This flexibility enhances the expressiveness of performances by allowing detailed control over individual notes within a polyphonic context.

MPE Emulator also supports independent transposition for each side of a keyboard split, enabling extended range capabilities or differentiated expression settings across zones. Its refined user interface simplifies controller selection, and the plugin is available in multiple formats, including a streamlined Lite version for REAPER that operates across various platforms. The plugin has undergone numerous updates to improve stability and compatibility, including fixes for parameter initialization, MIDI message handling, and integration with popular DAWs such as FL Studio and Ardour. These updates ensure smoother performance and better adherence to the MPE standard.

Despite inherent limitations within the VST 3 protocol regarding MIDI event ordering, MPE Emulator implements workarounds to maintain consistent polyphonic expression. While some DAW environments may present challenges, especially with VST 3 plugins, the VST 2 version offers full MIDI support where the host allows it. The plugin respects synthesizer capabilities by focusing on pitch wheel, channel pressure, and CC 74 for polyphonic control, aligning with common hardware implementations. MPE Emulator provides a practical tool for musicians seeking to enrich their MIDI performances with nuanced polyphonic expression, backed by thorough documentation and active maintenance.