XPI – Gamepad MIDI Input

XPI is a native macOS application that turns PlayStation, Xbox, and Switch controllers into expressive MPE instruments. It features a 5-layer harmonic wheel, a continuous virtual strumming engine, real-time voice leading, and true multi-port CoreMIDI routing—all backed by a built-in zero-latency DSP synthesiser.

It democratises Multi-Dimensional Polyphonic Expression (MPE) by mapping the high-resolution sensors in standard gamepads directly to musical parameters. Analogue sticks, gyroscopes, and triggers handle pitch bends, aftertouch, and timbre natively. Pairing this tactile hardware with an intelligent harmonic wheel and a physical velocity strumming engine allows non-keyboardists to perform complex, velocity-sensitive chord progressions with natural voice leading.

Allowing producers to compose rich, cinematic chord progressions and expressive MPE melodies entirely away from the desk. It overcomes the rigid physical limitations of a standard MIDI keyboard—translating the tactile muscle memory of gaming into fluid, multi-dimensional musical expression.