A Theremin in Garageband

My website logs show that someone was looking for my now-11-year-old tutorial on making a theremin in GarageBand. Shockingly, the instrument still works after all these years (probably because its generator is so simple).

The original tutorial is provided as-is herewith. Some adjustment may be required for modern versions of GarageBand. 

When Deirdre and I started writing "Captain" for our lyrics class assignment, we knew that a song about a defunct Sci-Fi actor would simply have to feature the theremin. Almost everyone with some exposure to western culture has heard a theremin before, they probably just don't know what it's called. 

The theremin, a musical instrument which uses radio waves to produce an eerie whistle-like sound which we associate heavily with campy 1950's-era Sci-Fi movies. Traditional theremins are still available from popular synth manufacturers. However, a real theremin costs upwards of a thousand bucks. Because of the way the theremin is played (see the Wikipedia article for more information), the sound is hard to properly emulate with synthesizers. However, for those of us who just want to pump out a few notes to make a cheesy sci-fi joke, a reasonable facsimile can be created using GarageBand

It took a bit of muddling about to create my own theremin. Here's a more condensed version which should allow you to create a similar effect: 

1) In GarageBand, create a new track, you should receive the dialog which allows you to choose an instrument for the track. Choose "Software Instrument". Then pick an instrument out of the synth categories that uses the "Analog Mono" generator. It doesn't matter which one (you can find out which instruments use this generator by expanding the "Details" arrow). You can't change anything really critical until the track is created, so hit the "Create" button.

2) Re-open the "Track Info" window by double-clicking the track. From here, we'll add several effect layers to produce our instrument. The first thing we need to do is adjust the settings for our generator:

3) The Analog Mono generator includes a "Glide" setting which controls a glissando between contiguous series of notes, an effect both ideal and essential for a decent theremin sound. Because the Garageband dialogs don't post numeric values, I can't give you the exact settings I used. So here's how the dialog looked when I finished my adjustments:


4) Unfortunately, the Analog Mono generator produces a saw-wave: a really buzzy sound which is utterly unsuitable. To make the instrument sound like a sine-wave, I applied the "Treble Reduction" filter and set it at about 50%:


5) Now our instrument is sounding more like a theremin. Another important effect is a healthy vibrato, which is applied by any theremin player looking for true cheese. Apply a "Tremolo" effect and use the following settings: 

6) Add whatever level of Echo and Reverb you desire. Now hit the "Save Instrument" button and name your creation "Theremin". The track info window should now look something like this: 


To get the funky glissando effect when you change notes, you'll need to make sure that the attack of subsequent notes is on or before the release of preceding notes. That is, hit a new note before the previous one is finished. By adjusting the "Glide" setting, you can create a theremin that has either a slow or fast glissando. You can also use the Pitchbend controller to add subtle variations to the theremin's melodic line (again, to simulate the musical idiosyncrasies resulting from the method of playing).

There you have it: emulated theremin in GarageBand! You can hear how I used my theremin in the song Captain.

Jesse Schooff