Category: Technique

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.

Example

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.

A rough form of synchronisation can be achieved by synchronising performer start times and using methods which fix the position of events within a piece. This approach can be used in combination with any other tool or combination of tools – screen space and devices allowing, but bear in mind that it will never allow for perfect synchronisation; things will always be a little ragged due to the effects of latency.

The simplest form is to use a clock which is centrally controlled in some way, which could be using a phone clock (reportedly most reliable if all performers are using the same type of device, e.g. all iPhones or all Android devices) or a service such as timeanddate.com, as in this image. Agree the time to start, then at that moment, all begin, regardless of what you can see or hear from the other performers.

Another possibility to consider is Chronograph, a cloud-synchronised stopwatch, which one person can start for everybody.

This approach can be combined, as in the image above, with video or audio scores or clicktracks.

Note again that this will reduce the desynchronising effects of latency, but will not eliminate them entirely. For the best results in audio-only work, consider using a low-latency audio tool.

Often in live online work there are multiple stages to be taken into consideration:

1. The stage of the whole piece
2. The stage of groups of performers
3. The stage of the individual performer’s frame
4. The stage of the individual performer’s physical environment

The stage of the whole piece

This is the entirety of what’s seen, the combination of all the performers’ stages and any additional material. This is the level at which videoconference presentation decisions are made, such as using the grid or working with Spotlight mode; and the level at which layout decisions are taken in OBS.

The stage of groups of performers

This is the way in which groups of performers combine onscreen, where patterns may form based on similarities of visible content, colour consistency, scale of performer/distance from the camera, etc.

Example

Jennifer Walshe: zusammen iii (Bastard Assignments Lockdown Jams 2020):

In this piece, Josh – in the top right corner – is differentiated from the other three performers through differing action, sound related to that action (the other performers are all silent), and makeup. The other three form a cluster – a chorus, if you will – based on the similarities of their actions (all switching between face yoga and silent speaking to camera), and contrast from the soloist.

The stage of the individual performer’s frame

What can be seen of the performer and their surroundings in frame, including their position in the frame, scale and level of detail (arising from how far they are from the camera). This is tightly aligned with the performer’s physical environment.

The stage of the individual performer’s physical environment

The significance of this ‘stage’ is in how it is arranged, used, and how it relates to the individual performer’s frame. This stage may feel somewhat intangible because it can be hard to define physically, but it becomes wider the further back from the camera you move, and you can make it feel more concrete by positioning objects just outside the boundaries of the visible area, so you can be aware when you are going ‘offstage’.

Videoconference software is designed for conversations. As such, it tends to have algorithms which prioritise one single voice over other sounds in the meeting. This means that instead of how we hear sound in when we’re in a group in person, with multiple people’s sounds all blending together, what we get is an interruption of a single line of sound when another sound is interpreted to be the most important. Thus, simultaneous sounding becomes interrupted.

What triggers this effect?

The driver is largely volume – louder sounds will be seen as more significant than quieter sounds, but this can of course mean that a loud background sound can interrupt a ‘speaker’, and of course breaks in a prominent part will allow fragments of quieter parts to be heard.
It is possible that visual triggers such as covering the camera come into play too, but this is unconfirmed. See the example in the next section (‘Looking down’).

Effect on visuals

This approach becomes visible particularly when capturing using ‘spotlight’ mode, where the view changes according to whose ‘voice’ the software deems most significant. This can be creatively interesting when it creates edits between parts:
Example: Bastard Assignments ‘Looking down’ for Lockdown Jams (2020):

It can also result in the effective excision of a group member whose sounds are quiet or who is working principally with visual material or whose internet connection is poor – if their sounds can’t be heard then possibly they won’t be seen either. To avoid this, try working with a different mode, such as grid mode.

Possible strategies

• Accept the interruptions! The internet behaves as an extra member of the group, disrupting and changing the material as you create it. Example: Bastard Assignments ‘Looking down’ for Lockdown Jams (2020) (above)
• Play with manipulating volume – change from loud to quiet or back again to give others a chance to be present.
• Using a grid mode, plan for one principal voice overall, with other members of the group working silently, or with planned periods of interjections. Example: Jennifer Walshe ‘zusammen iii’ for Bastard Assignments Lockdown Jams (2020):

Zoom

The position of performers onscreen is dependent on two things:

• Who is recording the session and
• The order performers entered the meeting

The position of performers can therefore be manipulated by using the Waiting Room feature – whoever is to appear in the top right corner should be recording the session and should be meeting owner. Once all performers are in the Waiting Room, the meeting owner can then let them in. Four performers will be positioned as follows based on their entry in this order:

1. Top right (meeting owner, recording)
2. Top left
3. Bottom left
4. Bottom right

Google Meet

We have not yet fathomed how to manipulate performer order in Google Meet’s grid view – it appears to be random – please update this if you have other information.

When participants are in breakout rooms and then these rooms are closed, it seems that they are released into the main call room by room, lining up left to right and top to bottom. Not sure if this is consistent though.

• Pro accounts of Zoom can apparently livestream directly to YouTube, but we haven’t tested this yet (please update this page if you can confirm this works)
• OBS can livestream to a single platform such as YouTube or Twitch
• https://restream.io/ will send a live feed to multiple services (we haven’t tested this yet but reports online seem to say it’s reliable). To livestream from a computer to Instagram, try Yellow Duck. If you want to stream to multiple platforms including Instagram, you can combine Restream with Yellow Duck: instructions here
• Google Meet will livestream to YouTube as an embedded feature in Google Workspace for Education Plus, Enterprise Standard and Enterprise Plus editions. This works well, with a c.10 second lag between the meeting and the streamed version.

See also:

• OBS