Prior to the digital age, life in the studio was all about moderating the effects of human touch.
Compressors evened out the dynamics of the bass player while a side chain feed kept them matched with the drummer. The drummer had a metronome feed playing to maintain tempo.
Singers, well, you could keep their dynamics in control, but when they sang flat, about all you could do was tell them to smile as they sang and aim above the problem notes.
Smiling has the mysterious effect of raising singers' pitch. Aiming high is probably wishful thinking on everyone's part, but sometimes it works.
The Advent of Auto-Tune
You wouldn't think earthquakes have a lot to do with singing in pitch and they don't, really.
However, it was seismic research that provided the background for Dr. Andy Hildebrand, the creator of Auto-Tune and its parent company Antares.
He left that field and returned to his early love of music, bringing knowledge that created seismic interpretation workstations and applied it to issues arising in the early days of digital music.
Hildebrand's expertise with digital signal processing led to a series of audio plug-ins, including 1997's Auto-Tune, which could correct the pitch of a voice or any single-note instrument with surprisingly natural results.
Audio engineers now had a weapon against the occasional bum note. Rather than scrapping an entire take, Auto-Tune offered a repair tool that quickly caught on.
Auto-Tune as an Effect
It was only a year later in 1998 that use of Auto-Tune as an effect rather than repair tool happened.
Called the "Cher Effect" after the singer's hit, "Believe," artificial and abrupt pitch changes came into vogue. Later, real-time pitch correction hardware brought both effects and repairs to the stage.
In the studio, Auto-Tune proved another weapon to "fix it in the mix."
Issues with Auto-Tune started soon after, with lines drawn between the purist and users camps. Many felt that using pitch correction was an artistic cheat, a way to bypass craft.
The arguments resemble the resistance synthesizers received in the 1970s and 80s that led Queen to note that none were used on their albums.
The other side of the argument pointed out that tools such as compressors and limiters and effects such as audio exciters had already been modifying the sound and behavior of voices throughout the history of recording. Though the anti-Auto-Tune camp seems vocal and large, rarely does a session go by without some use of pitch correction. It's nearly impossible to detect when used judiciously, nowhere near as obvious as when used for effect.
Auto-Tune is no longer the only player in the pitch correction game either. Celemony's Melodyne software substantially improves on Auto-Tune's interface and brought the full power of pitch correction to a plug-in ahead of the tool's originator, which still leads the pack when it comes to response and set-and-forget capability.
The Antares version of the effect has achieved "Kleenex" status. Its brand name is now synonymous with the generic effect it originated. It joins "Pro Tools" from the audio world and "Photoshop" from digital imaging in this manner.
Unlike some digital music signal processors, pitch correction hasn't generated a huge number of knock-offs. Melodyne is a serious contender, due to its far more intuitive interface. GSnap is an open source alternative that produces similar results. While iZotope's VocalSynth includes pitch correction features, it's more of a full vocal processor rather than a dedicated pitch correction app.
The 4 Best Auto-Tune VST Plugins
Now, lets get into the top 4 autotune plugins. Each one offers unique features and I assure you that one of these plugins have exactly what you are looking for
Antares Auto-Tune Vocal Studio
The originator is now a full-featured and functional vocal processor that still masters the innovative pitch correction duties it brought to the market, but adds a wide range of additional features and effects to help nail down the perfect vocal take.
Auto-Tune 7 forms the core of the Vocal Studio package, still tackling the pitch and time correction duties it always has. Since its earliest days, automatic and graphical modes handle the various chores for the main Auto-Tune module.
While still presenting a learning curve for the new user, the Auto-Tune 7 interface remains familiar enough for experienced users. Since it's the best-selling pitch correction software going -- and by a huge margin -- there are a lot of existing Auto-Tune users. Even if you're new to the plug-in, chances are you know someone who's used it.
The rest of the Vocal Studio package focuses on vocal manipulations such as automatic doubling, harmony generation, tube amp warmth and vocal timbre adjustment. The range and nature of these adjustments takes vocal processing into some new territory.
The MUTATOR Voice Designer lets you manipulate voices from subtle to extreme, permitting organic or alien manipulations but with results that still sound like voices, though perhaps not of this world. The ARTICULATOR Talk Box produces effects such as the guitar talk box of Peter Frampton and Joe Walsh, but also Alan Parsons-ish vocoder sounds, combining the features of sung or spoken voice with an instrument's output.
While the Auto-Tune Vocal Studio remains pricey, it remains at the top of a niche market of audio processing.
Melodyne 4 Studio
If Auto-Tune has a serious competitor in the pitch correction universe, it's Celemony's Melodyne. The interface, layout and operation of Melodyne is inherently more musical than the Antares take, so newcomers to pitch correction will likely find Melodyne easier to work with.
The Melodyne "blob" is an easy to grasp analog of a sung note. It's far more intuitive than a waveform to understand. With the focus on graphical interface, Melodyne makes sense more quickly and easily than Auto-Tune. The latter's switching between automatic and graphical modes creates a comparative disconnect between functions.
Even long-time users of Auto-Tune will find moving to Melodyne natural, as there's enough in common that, once a user gets their bearings, familiar functions remain available.
Many Melodyne functions perform on polyphony too. Correcting a track with a multi-voice choir or chording instrument can work too. It's not a perfect function, but it's uncanny how often Melodyne senses chords clearly enough to allow changing of a single element.
What Melodyne doesn't do is the advanced vocal pyrotechnics offered by Auto-Tune. The Celemony product is all about pitch and time correction and it accomplished these with grace and ease.
Those looking for an affordable entry into digital pitch correction can turn to Melodyne 4 Essential. It's a plug-in that handles the pitch and time corrections of its big brother, but with fewer advanced features and without the full-featured price tag.
Though pitch correction isn't the focus of this iZotope plug-in, it resembles the full Auto-Tune Studio package. At a fraction of the cost of the big boys in this class, VocalSynth doesn't offer the depth of control experienced with either Auto-Tune or Melodyne, yet it still manages to provide a reasonable job of pitch correction.
There's no graphical representation such as Melodyne's or Auto-Tune's graphical mode. That makes fine-tuning performances a little beyond the reach of VocalSynth, but for reasonable performances, it's not a major limitation. Think of the iZotope product as a first-aid kit rather than an emergency department.
The four voice synthesis modules are where the fun resides with VocalSynth. Talkbox, Compuvox, Polyvox and Vocoder modules emulate many of the vocal effects you've heard on hits from a wide range of artists. This is also just the most overt extra in the VocalSynth package.
A variety of additional modules let you tune up or tear up your vocal tracks. Add harmony, filter vocals, create radio and phone effects. These modules can either optimize your track or take it to new and exciting places.
VocalSynth may be the country cousin to the serious pitch manipulators, but it has capability with a high fun factor.
Don't let the download page fool you, GSnap is a VST plug-in that works with any DAW platform that supports VST, not simply Windows-based DAWs. Both 32 and 64-bit support is included. Completely free, it does come with limits. While there is more graphic information than iZotope offers, it doesn't offer direct edits.
While not as flexible as pro pitch correction, it's a low-cost alternative for users who can't swing the big time prices. It's difficult to use GSnap subtly. That's not an issue for those seeking pitch correction effects, such as Cher or T-Pain. Backup vocals are also a good candidate.
This is the entry level of pitch correction, and because of that, it's included here. The effect is so ubiquitous that anyone working in the field needs to know how it works. GSnap represents the place to start.
Wrapping It Up
Love it or hate it, pitch correction is here to stay, both as tool and effect. These four plug-ins aren't the only ones out there, but they represent the spectrum of pitch correction treatment. Auto-Tune is the originator. Melodyne is the refinement. It works just as well as the Antares product in nearly every way with an interface that easy to grasp.
iZotope VocalSynth represents the cream of the mid-priced plug-ins. It's capable and creative, even if it's not as flexible on pitch correction as the top-line apps. GSnap represents pitch correction for everyman. You can't knock the price of freeware.
The debate will likely rage over the ethics of pitch correction in popular music. While you wait for the dust to settle, give one of these packages a try.