AU, VST, Standalone / 01
A MIDI chord generator can run in a few different ways. AU is usually the Logic Pro path, VST is the most common cross-DAW plugin path, and standalone mode is useful when the chord tool should drive another app, device, or wider MIDI rig.
Section 01
Start with the format your DAW expects.
Logic Pro and GarageBand workflows generally start with Audio Unit. Ableton Live, FL Studio, Cubase, Reaper, Bitwig Studio, and Studio One workflows usually start with VST or VST3 depending on the host and platform.
That plugin route is best when you want the chord generator to live next to the instrument, arrangement, and automation inside one project. It keeps the setup compact and easier to recall.
Section 02
Standalone mode is for setups where the chord generator is its own instrument surface.
Standalone mode makes sense when Harmonimo should feed another app, an external synth, a network MIDI session, or a DAW track through a virtual MIDI bus. It can also be cleaner when controller mapping gets crowded inside the DAW.
The tradeoff is that you manage routing explicitly. The benefit is that the harmony tool can become a central MIDI source rather than one plugin inside one track.
Section 03
Use the simplest working route first.
For most sessions, start with the direct plugin format for your DAW. If you hit a routing limitation, move to standalone plus virtual MIDI. That keeps the normal case simple while preserving a route for bigger MIDI systems.
This is also the easiest way to troubleshoot. If the plugin route works, you know the DAW and instrument chain are healthy. If you move to standalone later, you only need to solve the MIDI handoff.