Virtual Music Sessions

In the current Coronavirus crisis (March 2020), physical meetings to play music together have been banned. I have therefore been investigating use of generic conference calling software, such as Skype or Zoom, to see how they might help keep musical communities together.

Chat/Conference Call Software

Many will be familiar with online video/audio chat applications like Skype, Zoom, Facetime, Facebook Messenger, WhatsApp, Google Duo or Hangouts, or Microsoft Teams. Some of these (Duo, Facetime, etc) are aimed at one-to-one calls, and probably are not scalable to largish groups. Others like Teams are more optimised for business enterprises.

Simplistically, one might assume that the middle ground (Skype or Zoom) which work well for group voice conversations between several members joining a business or family conference would also work well for jointly playing music. However, there is a big problem and that is latency (lag).

Latency

This is not really caused by slow physical connections. Electrical signals only achieve about a tenth of the speed of light, but that’s still 18,000 miles per second. The long-distance fibre optic links can get much closer to lightspeed. There is still some delay in both ends of the optical link though.

The main cause of latency in networks is packet buffering - the transmitter has to split the communication into a series of packets of information to send through the physical network. Routes through the Internet are dynamic and not totally reliable at the lowest levels. Each packet could go via a different route, or one or more packets may get lost. The receiver device puts arriving packets into a memory buffer, to sort them in order, and requests retransmission of any missing. It waits for the latency period for this to happen before releasing the buffer to the application program.

Typical latencies seen by video/audio calling software seem to be between 100ms and 500ms. That’s 1/10 second to 1/2 second. To voice chatting, this is not a big problem – we can cope with sub-second delays. You may notice that people’s lip movements don’t match the sound. But to a session musician, it’s horrendous – if you are listening and playing, then you would be heard as playing two or three notes later in the tune!

So, What Can we Do?

The good news, is that latency is not a problem if only one person is playing at a time. So, Zoom or Skype would work for a “round the room” session, where each person plays or sings in turn. Also OK is the scenario where one person – a teacher or leader, is playing to be heard by several others. It even works for them to play along with the teacher, provided that the student’s microphone is muted, so that their delayed notes don’t get back to the teacher or other students.

A further possibility is for each member to listen to the leader through Skype or Zoom on headphones, while playing along. If sound is recorded locally into an audio file (MP3 or similar), and that sent by email back to the leader, then he/she can use audio editing software like Audacity to merge the contributions into a combined performance. That is quite a lot of non-trivial work though, to get the recordings lined up and merged.

Practicalities of Using Zoom

Finally, we recently did some experiments using Zoom, and I have some specific points to note regarding using that application for a group music call. To use Zoom, the leader goes to Zoom.com (or zoom.us) and registers as a user. Then click on “My Account”, then “Meetings”, then “Schedule a new meeting”. This lets you set time etc. When you hit Save, it will generate a “Join URL”, like https://us04web.zoom.us/j/328786995 which you can email to everyone. It actually has an option nearby to generate an invitation text containing this URL to make this easier.

At or just before the appropriate time, everyone clicks on the link in their email. If it is the first time for them, they then are prompted to download the Zoom application and login. A Zoom app is available for Windows, Mac, Apple iOS, Android, etc, so most PCs and tablets. The first time, you may be prompted to check microphone and camera (for people who haven’t done any video chatting before, it may be worth trying Zoom out beforehand one-to-one). Once the leader/host has joined, everyone else can join in.

Thumbnails for users appear along the top of the screen, and the ‘active’ user (the one who is speaking) fills the screen. Controls are at the bottom of the screen for e.g. muting your microphone, turning on/off video, chatting, etc. The leader/host has further controls, e.g. Manage Participants which lets him/her mute all participants, and unmute specific people.

Original Sound option of Zoom

Zoom, like Skype, tries to make clear the audio from one person at a time, so don’t butt in while someone else is speaking. Zoom specifically identifies speech, and treats other sounds as background noise, and tries to supress them. This is a problem if the ‘other sounds’ is someone playing a musical instrument, intending to be heard, as Zoom will realise its not speech, and supress it! There is a solution/workaround in Zoom, called “Original Sound”. Each person playing has to go to Settings, Audio, and click on the Advanced button at the bottom. At the top of the next screen is an option to display an “Original Sound” option in the app. Once this is enabled, back in the main app window, there will be a button top left saying “Turn on Original Sound”. If you click on it, it turns blue, and changes to “Turn off Original Sound”. This will stop Zoom supressing your music! It’s best however if only the person currently playing has this option turned on (blue).

Final Thoughts

Zoom does a good job with video as well as audio, but for a largish group (more than half a dozen), then it may be best to start with video off for everyone, and just enable it for the leader, or for someone else who is playing.

As well as the generic tools like Skype or Zoom described above, there are also a few more specific music applications such as JamKazam. However my attempt to use this was unsuccessful, and its web site seems to have been dead for several years. So it does not seem to be a good candidate at present, and therefore is outside the scope of this essay. If you make it work well - let me know!

Happy experimenting and playing. May your music give you strength through these adverse times!

[Paul Hardy, 2020-03-25]


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