While not live, ‘virtual choir’ recordings form a significant proportion of online performance production, especially for music. The name ‘virtual choir’ refers to Eric Whitacre’s virtual choir project which has been creating recordings in this way since 2010.
A virtual choir recording is made entirely offline. Each performer is provided with either a clicktrack or a backing track of some sort, which they listen to on headphones while performing their own part. The solo performance is recorded, usually on video, but it could be just audio, or video and audio separately but simultaneously (e.g. video on a phone, audio being captured in high quality on a Zoom recorder). The recording(s) are then sent to a video/audio editor, who compiles the track from the individual recordings.
The results can be artistically satisfying and impressive, but this is not a live medium. It is, however, the best way to create recordings of precisely synchronised music by performers who are geographically remote. For a live alternative, consider low-latency audio tools.
Visit https://www.nrk.no/video/musikk/kork–all-by-myself-korona-edition_ca5aabe6-b292-466a-9c4e-a6bbe4e43bcb for a marvellous early-pandemic virtual choir performance of Celine Dion’s ‘All By Myself’ by the Norwegian Radio Orchestra.