Harmodion is a virtual instrument that combines the sounds of organ and free-reed aerophone instruments, including electronic organs, clonewheel drawbar organs, transistor and combo organs, as well as reed harmoniums, flutinas, accordions, and bandoneons. It employs additive synthesis to manipulate sine wave components harmonically and inharmonically, allowing for a broad range of pitched and textured sounds. The instrument features sliding drawbars that mix harmonic components generated by tonewheel emulation, enabling the creation of diverse and richly layered tones.

With 64 presets covering genres from blues, jazz, gospel, and rock to folk, ethnic, and popular music, Harmodion offers a wide palette for sound design and musical expression. Users can customize sounds by adjusting nine drawbars to blend pitches and shape the distinctive character of electric organs or free-reed instruments. The synthesis engine allows reshaping of timbres from harmonic to inharmonic textures, supporting emulations of classic combo organs like the Farfisa Compact and Vox Continental.

Additional features include vibrato with adjustable depth and speed, key click simulation for authentic percussive effects, and configurable drive that adds warmth and sustain by clipping the input signal. The instrument includes a preset manager for easy loading, saving, and exporting of presets in multiple formats. MIDI automation support enables seamless integration with hardware controllers and DAWs, making Harmodion a flexible tool for both studio production and live performance.