Chorus Ex Machina is an open source, physically modelled chorus synthesizer. It can sing realistic sounding text in a variety of languages. Here is an example of music created with it, so you can hear what it sounds like.
The sound produced by Chorus Ex Machina is completely dry. It models only the singers, not the room they are in. To get a realistic sound, it is essential that you add an appropriate reverb.
Chorus Ex Machina can be used as a VST3, CLAP, or AUv2 plugin. The Releases page has compiled versions for Windows, Linux, and macOS. If instead you want to build it from source, first install the Rust compiler. To build the VST3 and CLAP plugins, execute the following command from this directory.
cargo xtask bundle chorus_ex_machina --release
To build the AUv2 plugin, first build the CLAP plugin then follow the instructions in
the au subdirectory.
For instructions on how to use the plugin, see the documentation, which is also available in the plugin's user interface.