How to Use Refractions as a MIDI Synth in Apple Logic

Let’s say we start with a audio track and we want to use that sound as the audio source for Refractions:

A screenshot of Logic Pro on macOS showing a single audio track

Your instinct might be to put Refractions directly on that track. Don’t do this. Instead, create a brand new Software Instrument track:

The new track will have some new instrument assigned to it (in my case the instrument was Logic’s own Sampler instrument). Click on the instrument to change it:

You’ll want to select Refractions from the AU MIDI-Controlled Effects sub-menu:

At this point, the Refractions user interface will pop up. Select MIDI Synth from the Pattern list:

Next, in the top-right corner you should see a menu that says Side Chain. Select the audio track containing the audio you want to use as an audio source. In our case, that is a track simply called “Audio”:

That’s it! At this point, all that’s left to do is to write some MIDI on that instrument track. As soon as you hit Play, you should hear sound coming from your speakers: