One of my favorite new products at the massive NAMM musical-instrument show was the DigiTech Vocalist Live, a stompbox that listens to your guitar playing and automatically generates vocal harmonies. There's no complex configuration or hexaphonic hardware; you simply plug a guitar and a mic into the Vocalist's audio inputs and then strum and sing.

The Vocalist just started shipping last week, but O'Reilly Digital Media blogger George "the Fat Man" Sanger has had a prototype since March. He was so impressed that he wrote, "Do you sing and play guitar? You must buy this."

I called the Fat Man at his Texas studio via Skype to hear what he likes so much about the Vocalist Live. He played a bunch of fun examples and revealed what happened when he unleashed this bold new technology in a jam session. (DMI 06-28-2007: 19 minutes 26 seconds)

Production Notes: Recording

To overcome Skype's dodgy audio quality, the Fat Man and I recorded the interview using a radio-broadcast technique called a "two-ender": We used Skype for communication but simultaneously recorded each side of the conversation locally with better mics in a higher resolution. The Fat Man then sent me his recording as a 160Kbps MP3 file, which I aligned with my side in Ableton Live 6.

He used Steinberg Nuendo to record. I used Ecamm Call Recorder and my Logitech USB headset. I considered using the much better-sounding Rode Podcaster mic I typically use for the show's voiceover, but couldn't get it positioned comfortably on my desktop. I also wanted to record at a higher level than it puts out. Call Recorder captured both sides of the conversation to a QuickTime file, although my side sounded far better, because it was local.

Of course, that's the point of the two-ender technique: The Fat Man's Skype vocal was for reference only. Once I had his recording, I simply dragged it sideways on Live's timeline until it matched up with mine, and then I muted his Skype track.

Digitech Vocalist Live 2

The Vocalist Live 2 generates two harmony notes for your voice based on what your guitar is playing. It can also compress your voice for smoother dynamics and add reverberation. (Click to enlarge.)

Mr. Fat threw me a challenge, though, by recording his entire vocal through the Vocalist Live 2, bypassing the harmony effect (usually!) when he wasn't demonstrating the stompbox. The result was a dual-mono file, with his reverberant voice on the left channel and his guitar signal on the right. I used BIAS Peak 5 to split it into two mono files I could load into Live and edit independently.

Korg PXR4

To see what would happen, I dragged the Skype recording I made (blue track) and dual-mono MP3 the Fat Man made (pink track) into Ableton Live. I was pleasantly surprised to see that Live displayed the text markers I'd typed into the recording. But Live was unable to recognize the file's weird multitrack format, so I extracted the two sides with QuickTime Pro and started over.

Editing and Assembly

With previous interviews, I've done the bulk of editing and cleanup in Peak, but in this case, I had three synchronized tracks: my voice, the Fat Man's voice (both straight and harmonized), and his guitar. Because Peak handles only stereo files, I turned to Live instead, using volume envelopes to mute our respective vocals when the other person wasn't talking. (There was an annoying microphone bleed between the tracks.) Another challenge was that the Fat Man's vocal level jumped drastically when he turned on the harmony effect, so I did a lot of sculpting with volume envelopes to even it out. You can see the level difference in the screenshot above.

I then used BIAS's SoundSoap plug-in to remove the hiss from my vocal and the guitar track. To restore some of the spaciousness of the Vocalist's stereo output (which we'd recorded in mono), I added a touch of reverb with Izotope Ozone. (The bulk of the reverb is from the Vocalist.)

As mentioned, I usually record my voiceover with a Rode Podcaster mic, but I just received an SE Electronics USB2200a mic for review, so I tried that instead. I've been disappointed with the Rode's low output level and susceptibility to electrical noise, both downfalls the SE is supposed to fix. I recorded directly into Peak, with the SE in USB mode.

Next, I imported the voiceover file into Live, where I arranged it around the interview audio and the theme music. I compressed and enhanced the voiceover with Ozone. Finally, I rendered the mix to an AIFF file, converted it to an MP3 in Peak, and then imported it into iTunes to clean up the ID3 tags and add artwork.

The Digital Media Insider theme music came together in Live as well. The opening sound effect is a compressed mouth noise spliced onto a tone cluster I generated in Native Instruments Reaktor. The main groove is from Steinberg Xphraze. (Jim Aikin turned me on to both virtual instruments in his article "My Five Favorite Soft Synths.") The piano is from the Garritan Personal Orchestra, which I discovered when we interviewed Gary Garritan. Then there are a few percussion samples dredged from my hard drive. Altogether, the theme took just six tracks. Effects processing was courtesy of Live's default plug-ins and Freeverb.

Aerosol Grey Studio

Ecamm Call Recorder saves Skype calls as multitrack QuickTime files. The caller's voice is mono, but the recipient's is dual-mono. The text track contains location markers I typed in during the recording. Selecting a track and clicking the Extract button allows you to save individual tracks to new files.

Related O’Reilly Articles and Blogs

New Music Technology at NAMM 2007

We spent four days exploring America's biggest musical instrument show to bring you this gallery of new (and sometimes bizarre) music technology. See and hear what you'll be playing tomorrow.

Do You Sing and Play Guitar? YOU MUST BUY THIS

"You know how I am…I never recommend gear, I just wax all philosophical about theories and such," writes the Fat Man. "However, I am currently so stinking excited I can’t sit still! Don’t tell the other guys; we jam tonight, and I have the coolest secret weapon ever."

How to Make Your Sound Sing with Vocoders

In this hands-on tutorial, Jim Aikin explains how vocoders perform their magic, how to set up your own software vocoder, and some unexpectedly cool uses for vocoding.

Digital Media Insider Podcast 2: The Vocoder

Hey, Cylon breath! Think vocoders are good for only robotic sound effects? Hear how top musicians are using them creatively as we dive into the expressive sounds behind four recent features.

Review: M-Audio Black Box, v2

This breakthrough guitar processor offers amp modeling, unique rhythmic effects, a mic input, a drum machine, and a Pro-Tools-compatible USB audio interface for an astonishingly low price. Our impressed reviewer concludes it deserves a place in every guitarist's setup.


The Fat Man—Home of the biggest name in audio for games.

3dB Research—The scientists behind the Vocalist Live's MusIQ harmony technology.

DigiTech Vocalist Live 2—Product page, including video demos.

Line 6 Variax—The guitar the Fat Man plays in this episode.

SE Electronics USB2200a—This new condenser mic features both USB and XLR output jacks for simultaneous digital and analog recording. Its unique voltage-conditioning circuit is designed to minimize USB electrical noise. A headphone jack lets you monitor your voice with zero latency.

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