Harmony Engine is a real-time harmony generating plug-in that lets you produce professional quality harmony arrangements from a single vocal or monophonic instrument track.

VST3
- A compatible VST host program that supports VST3 format
- macOS 11 and higher as required by your host

Audio Units
- A compatible host program that supports the AU format
- macOS 11 and higher as required by your host

https://www.antarestech.com/products/vocal-effects/harmony-engine