Here are some easy, lightweight, plug & play options for sharing music from a MIDI keyboard over Zoom.
MIDI keyboards don’t usually generate sound. You need to plug it into a synthesizer or computer. Here are 4 broad types of options.
For the best chances of success, plug the keyboard in before opening an app. For web apps, use Chrome if possible. In many cases, you also have to select your MIDI keyboard model as the MIDI Input. Audio Output should be the model of your speaker or headphone.
1. Online rooms
EASIEST. With a shared link, people on the other end can listen and even jam from the browser. No zoom is required at all.
2. Online synths
These web apps generate sound from your MIDI keyboard, but you’d have share it through Zoom.
In Zoom, select share screen, select your browser, and tick shared computer sound.
For sound only, select share screen, go to the advanced tab, select share computer sound only.
My pick: https://dotpiano.com/
https://synth.playtronica.com/ https://www.webaudiomodules.org/wamsynths/ https://www.gsn-lib.org/apps/cardboardsynth/index.html
Online notation apps like Flat also have in-app keyboards: https://flat.io/help/en/music-notation-software/midistart.html. To play instead of edit, turn off write while playing.
Note: Web apps are not secure; some explicitly broadcast your music. So don’t encode your bank account number as musical notes.
3. Downloadable synths
Mac users rejoice!
There’s still all sorts of piano apps for Windows users, like https://sourceforge.net/projects/freepiano/.
If you don’t like default sound(s) of the apps, there’s a whole wide world of VST instruments. Many are free, some cost you an arm and a leg. You can load VST’s into your DAW, or use a VST host like https://www.tone2.com/nanohost.html or https://www.cantabilesoftware.com/. Here’s some free piano VSTs: https://blog.landr.com/best-free-piano-vsts/. Some, like https://www.native-instruments.com/en/catalog/free/ also provide a standalone app. This is a rabbit hole I’m not diving any further into…
Last but not least, audio applications often override or bypass normal sound settings, meaning Zoom sometimes doesn’t pick it up the audio at all. (This is why I’m kinda enamored by the web synths.) Test your setup over Zoom with a friend. If it doesn’t work, try the following.
For Mac users, Zoom has a ZoomAudioDevice that your DAW can output to.
If nothing else works, you may have to route your computer sounds (and microphone output) into a virtual input, and then get Zoom to recognize the virtual output as its input. These are super finagly. Here are two popular audio routing apps: https://rogueamoeba.com/loopback/ (Mac), https://www.vb-audio.com/Cable/ (Win).
4. Go Acoustic
Swap your MIDI keyboard for a portable electronic piano (which usually includes MIDI out) or a melodica. Make sure you enable and turn on original sound. https://support.zoom.us/hc/en-us/articles/115003279466-Enabling-option-to-preserve-original-sound
The melodica is young Jacob Collier’s instrument of choice.