Zoom quickstart guide for music classroom teachers

My basic tools are a MacBook Pro, an external monitor, a portable document camera, and a portable electronic keyboard. The discussion assumes those tools and that OS.

Options for what the screen displays

When you’re hosting a zoom meeting, you always have the option to share your screen. It’s a green button, one of the options on the toolbar at the bottom of the window.

When you click share (or new share, if you’re already sharing), you get a new window with a choice at the top for basic or advanced options (the first default is basic, but then it displays whatever you were on when you last used it).

Under basic options, you get the following choices:

After you make a selection, you have to press “share” at the bottom, and that step makes it a slower process than just changing windows on your desktop. Beyond the delay of clicking buttons (and worse, it seems), there can be an extra delay on the participants’ end after your make the selection. If you expect to swap windows often, sharing the desktop will probably make those changes smoother. (I originally planned to share the second desktop on my external monitor, swapping windows on that desktop, and keeping my laptop desktop for notes and audio player controls. In practice, just going to the window each time seems to work ok. The flow online is just slower, so the pause doesn't bother me as much as I thought it would.)

Under “advanced,” you have the option “content from 2nd camera.” This broadcasts your webcam (and not your document camera if that’s also attached, I don’t know why it calls it a 2nd camera). Why share your webcam as a screenshare, isn’t that the default mode? The answer is that this allows you to broadcast audio from your computer at the same time, as discussed below. So if you want your students to see you while listening to music that you play, or while talking while playing the keyboard, that’s the way to go. But note that video and audio will not be well synchronized; if you need precise timings as you conduct or otherwise gesture with the music, it won't work. The sync seems to be better in regular mode, without screenshare, though just how good it is depends on your internet connection, as well as on the viewer's connection. More on audio/video synchronization below.

And funny things that are good to know:

Sharing audio from your computer

If you want to broadcast music (spotify, iTunes, a keyboard), or use any sound other than what comes in through your microphone, you need to be in screen share mode. (Depending on your internet speed, you may want to avoid broadcasting media that you are streaming.)

When you choose “share” or “new share,” whether you’re on the basic or the advanced tab, the bottom left has a checkbox called “share computer sound.” That sends your machine’s total sound output to zoom; otherwise only your microphone gets sent. (Obviously, you’ll then need to control volume in each sound application separately to get the balance you want.)

For each meeting, you need to check this box when you first want to share computer sound, but then for each new share it defaults to the last option for this, so it’ll stay checked through a zoom class as you switch from window to window via new shares, if that’s what you do.

Synchronization problems between multiple sources

These are very significant. Video is not synchronized with any audio source. Different audio sources are not synchronized with each other. The extent of the problem varies from participant to participant, but it is noticeable even on recordings made in zoom with no participants. (So the zoom record feature is not a good way to produce demonstration videos of this sort for your students.)

I do need good sync for some things I do in class, for example using Curwen hand symbols to show chords while listening to pop music, or conducting hypermeter. So I've started making videos and uploading them to canvas (the learning management system we use at CMU). Either they watch them on their own ahead of class, or I tell them to watch on their own (not via zoom) during class, using the "raise hand" to signal when they're done. To make these videos I use Screenflick, which is offering free educator licenses that are good through June 1, 2020. (Thank you Screenflick!)

Unlike Quicktime, Screenflick can capture system audio while recording through the laptop's camera. The Screenflick camera capture has the best sync with audio, but since the software is meant for making films that show what you're doing on screen, the camera is at most a little box at the corner of the window. So I prefer to just capture from the screen, using a quicktime recording window to bring up the input stream from the camera. Another really nice feature of Screenflick is that it has a basic clip trimmer built in, so before exporting the video you can trim off the places where you're starting things up and stopping things. I find I need to anticipate a bit to have the sync come out well, and it's good to use smooth motions, as the chances are that a quick, staccato gesture won't line up with the sound. But I just go into orchestral musician mode, and it works out :)

The one thing I've found to be aware of is that Screenflick sometimes basically mutes your sound because it was taking your system audio. This isn't a problem while using it, I think it happens after, maybe after you quit the application sometimes. But this is easy to fix by going into "sound" in preferences and under "output" selecting your usual output source (deselecting "screenflick loopback").

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