HarmonyAngel app icon

MIDI harmony processor

HarmonyAngel

Turn one monophonic MIDI line into chord-aware harmony from a fullscreen iPhone/iPad performance interface or an AUv3 MIDI processor host.

For MIDI performers

Chord slots, progressions, harmony shaping, and AUv3.

HarmonyAngel follows the active chord while you perform. Choose chord slots on two pages, play from a MIDI controller or the on-screen piano, and generate descending chord tones below each incoming note.

The app is designed for keyboardists, composers, producers, worship musicians, live performers, and anyone who wants fast chord-aware harmony from simple MIDI input.

  • Two pages of 12 editable chord slots, including no-harmony slots.
  • Built-in chord types, slash roots, and custom chord definitions.
  • Progression controls for stepping through saved chord sequences.
  • Harmony count, root alignment, skip-first-harmony, and revoice controls.
  • Standalone CoreMIDI use, built-in sine synth testing, and AUv3 MIDI processor support.
HarmonyAngel iPad layout with chord slots and piano controls HarmonyAngel iPhone portrait layout

Local-first privacy

HarmonyAngel does not collect user information.

No analytics No tracking, account, or usage analytics are collected.
Local MIDI and audio MIDI and audio are used only for local performance features.
Device storage Settings and musical data stay on the user's device.