The app provides a practical tool for testing, comparing, and developing harmonic ideas.

Enter a melody with the virtual keyboard, then generate a chord progression for it. The starting chord can be chosen manually, or the app can select a suitable starting chord based on the first note of the melody. Harmonization is based on rules, relationships between chords, and voice-leading constraints — not simply on probability. This makes the app especially useful when the goal is to examine several possible harmonic directions instead of receiving only the most conventional solution.

The melody can be shown on a staff, played back on its own, or played together with the generated harmony. Adjust tempo, note durations, chord-form preferences, the scope of harmonic selection, and the instrument used for internal playback. Chords can be excluded, individual melody positions can be locked so that no chord change is added there, and a completed harmonization can be saved and shared as a MIDI file for further use.

Melody Harmonizer is suitable for exploring harmonic ideas for hymns and other monophonic melodies, sketching choral arrangements, and supporting the study and practice of harmony. The input melody may be clearly tonal, more freely tonal, chromatic, or experimental; the generated result is nevertheless approached from the perspective of classical tonal harmony.

Key features

-Melody entry with a virtual keyboard, up to 48 notes
-Staff notation view with chord symbols
-Harmonization with a user-selected or automatically chosen starting chord
-Adjustable tonal, modulating, and more expressive harmonic selection modes
-Key estimation based on the melody
-Adjustable note durations, tempo, and base note unit
-Chord exclusion and chord-form preferences
-Option to favor contrary motion between melody and bass
-Save melodies and settings in memory slots 1–20
-Playback with internal instruments: piano, strings, guitar, and choir
-Save and share the finished harmonization as a MIDI file
-If you want to leave a note without harmonization, click its sequence number and it will turn red as a mark.
-If you want the enharmonic equivalent, click the note head.

Who is it for?
Melody Harmonizer is intended for users who want to examine a melody from a harmonic perspective and find new options for arranging, accompaniment, or improvisation. It is especially useful when the starting point is a simple melody and the goal is to discover several possible harmonizations that can be developed further.