One of the most beautiful effects you can put on a track is the sound of a large vocal ensemble. In the old days, you had two options. The first was to hire a massive choir to sing in perfect harmony. The second was to record hundreds of vocal tracks, all hitting the right notes perfectly, and then mix it down with painstaking attention. Today, there’s a third option. It’s called Harmony Engine and it produces the same effect both instantaneously and with stunning realism.

Harmony Engine delivers the sound of a 32-person vocal ensemble from a single human voice.

I’m Not in Love (With Painstaking Workflows)

To understand how harmonizers work in context with a track, the best reference is 10cc’s classic hit, “I’m Not in Love.” To create the effect, 10cc’s Eric Stewart recorded the band’s other three members singing 16 different iterations of the vocalization “ahhh” for each note in the chromatic scale. Each was laid down as a tape loop, creating 48 different loops per note, and 576 loops in total. These loops were then faded in and out with a mixer. The result was one of the most pioneering and dramatic vocals effects ever recorded.

It’s a beautiful effect, but it’s worth noting that it took Eric Stewart three weeks to produce. With Harmony Engine, the process takes just seconds and can be generated from a single human voice.

Listen to 10cc’s pioneering use of vocal harmony as a creative effect.

The Wizard of Ahhhs

Let’s take a listen to how we can use Harmony Engine to produce a similarly dramatic effect. In the sample below, you can hear a simple loop of one sustained, vocalized note–similar to how 10cc started things with “I’m Not In Love.” (I’ve also added a little reverb for atmosphere.)


To see how we accomplished this, take a look at the screenshot below. I’ve adjusted the Humanize controls to add natural vibrato and timing variation to the virtual voices. That’s a key feature because it allows you to create an effect that doesn’t sound like a bunch of clones. There’s also a global Glide control to smooth transitions between notes, and dedicated Vibrato controls which we’ll discuss when looking at the voices.


On the next screenshot below, you’ll see the controls that you get individually for each of Harmony Engine’s four harmony voices.



Interval lets you select a harmonic interval relative to the input pitch. Throat Length lets you adjust the formant sounds to give each voice its own unique character. Vibrato makes the voices sound even more realistic and independent. You can choose the rate of modulation, when the vibrato starts, and how much it will affect the pitch and amplitude. (For a more natural-sounding ensemble, keep the Vibrato settings similar across the different voices.)

Expand at Scale

In Scale Interval mode, you can choose a global scale and set voices to scale intervals, rather than raw semitones. Listen to the examples below.

The note sung is in E major, so Harmony Engine is set accordingly


You can also multiply things exponentially using the choir feature. The choir effect can be enabled or disabled individually for each of the four voices and the original input voice. You can add up to 16 extra voices per voice channel for a total size of up to 80 voices.

Let’s hear that phrase again with choir enabled.

 Harmony Engine Inspiration

We’ve barely scratched the surface of what Harmony Engine can do. But as you can see it gives you a lot to work with. If you’re ready to explore the possibilities with Harmony Engine, download a free trial of Auto-Tune Unlimited. Available through subscription, Auto-Tune Unlimited comes complete with Harmony Engine, all of the AVOX plug-ins, every current version of Auto-Tune, and more. It also offers the lowest cost-of-entry to access the most comprehensive collection of pro vocal effects ever offered from Antares. Just click here to start your subscription, or try it out for 14 days at no cost.

Auto-Tune Unlimited comes complete with Harmony Engine, every current edition of Auto-Tune, and the entire collection of AVOX plug-ins.