Creating virtual midi devices on macOS is a useful way of testing applications and interconnectivity… But how is it done?
So recently I’ve been working on a browser-based WebMIDI application I’ve named keybaud.io… and whilst I’m not ready to go into detail about that just yet, I am finding that it’s useful to have test MIDI devices that don’t require hooking up external gear. Fortunately macOS makes that pretty easy using built in functionality. Here’s how it works.
First we need to find and run the “Audio MIDI Setup” application. This can most easily be done using the Spotlight search (the magnifying lens icon on your menu bar):
Once the application is running, we will need to show the “MIDI Studio” window found by clicking here:
And from there we will configure the “IAC Driver” by double-clicking it. Name your device and ports however you prefer, but be sure to check the “Device is online” checkbox. It should look something like this:
Once you hit Apply you should be good to go! Now when you use virtual devices such as VMPK (or WebMIDI), you can set their destination output to your IAC Driver. If you have (or desire) a more complicated setup, you may wish to add extra ports or change the channels as needed.
