The Subtle Art of Pitch Correction
Mix engineers today are asked to do far more than simply mix the song. In fact, it’s now expected that they clean the tracks, eliminate pops and clicks, adjust the track timing, and replace or augment some of the sounds as well. Another job that falls to many mix engineers today is correcting the pitch of any track that needs it. This process is faster and easier than ever, but like anything else, you still need good fundamental technique to seamlessly pull it off. Here are some tips and tricks for correcting the pitch of any vocal or instrument, as outlined in my latest edition of The Mixing Engineer’s Handbook.
While it’s easy to believe that pitch correction only became possible with the introduction of Antares’ breakthrough plug-in, Auto-Tune, in 1997, the process has been around since the 1970’s, starting with the first Eventide H910 Harmonizer. Primitive as it was, the H910 did allow for slight pitch corrections, although the digital artifacts that it imposed on the sound were quite substantial the farther you strayed from the original pitch. As newer versions of the Harmonizer (and later the French Publison Infernal Machine) were released, engineers could get a wider range of correction before the digital artifacts became noticeable, but the bulk of the work was still all done manually.
To give you an idea what “manually” actually meant, the engineer would locate the point in the track that needed correction, set the Harmonizer to the correct pitch, rewind the tape, play it through the Harmonizer, then either record it on to another track or a different tape machine, which then had to be recorded back onto the master in sync. Needless to say, it was a tedious process to correct even a single note. Of course, studio owners back then loved to hear that a project decided to tune vocals since the bill for studio time would expand substantially.
Today things are obviously much easier, thanks to plug-ins that would simply astound any engineer transported in time from back then.
Getting Started With Pitch Correction Plug-Ins
Two of the most popular track-tuning programs commonly in use today are Antares Auto-Tune and Celemony Melodyne, but there are many others to choose from as well. Be aware that all tuning plug-ins impart their own sound on the audio that you’re tuning — and it might not always be pleasing. Many engineers typically own several different ones so they can compare which sounds better in a particular situation.
Except for the occasional case where you really want it to be obvious — like Cher and T-Pain — you’ll want the listener (and sometimes the artist) to be totally unaware that the pitch has been manipulated. Here are some things to keep in mind:
- Use the performance itself first. Before you apply pitch correction, try to find other parts to use in the performance to keep any correction as natural-sounding as possible. These including vocal comping and copy and pasting phrases, words, or syllables from other parts of the song.
- A little goes a long way. The fewer notes you correct, the more natural your performance will sound. You’re much better off just correcting a few notes than attempting to correct a large portion of the entire performance. If it’s that far off, you should try to get that part recorded again.
- Use the most precise mode. Auto-correct modes may be designed to make things turnkey, but they’re often not precise enough for most applications. As a result you may get audible fluctuations that make the track sound artificial — which is usually not what you’re after. If the plug-in has one, use the graphical mode to achieve the most precise tuning with the least amount of audible artifacts.
- Don’t worry about perfectly tuned vocals. Even the best vocalists are never precisely on pitch — that’s what makes them unique. Getting the pitch within a few cents will sound more like the real thing, since it’s the variations and inaccuracies that make a human voice sound human.
- Print the pitch correction. Instead of leaving the pitch correction patched in as a plug-in, you’re better off printing a corrected pass and using that track instead. This saves precious system resources and also eliminates any problems that might occur if the session is moved to a different DAW.
A Few More Tips
Here are a few tricks often used when correcting the pitch of a mix element. As always, don’t be afraid to experiment, since slight variations might fit better on a particular mix.
- Experiment with harmonic resonance. Sometimes raising the formants (the harmonic resonance) of a voice can make the vocal sound a bit more exciting or breathier. It doesn’t actually change the pitch — just the placement of the voice’s harmonics.
- If the vocal is off enough that the pitch correction sounds robotic, try this trick. Copy the vocal to two additional tracks and spread them left and right. Tune one of the vocals up by 2 to 8 cents; tune the other down by 2 to 8 cents. This will smooth out an out-of-tune vocal and make it sound a lot thicker at the same time.
- Try adding some reverb. Tuned vocals almost always sound better with a least a touch of reverb or delay on them.
- Be gentle with lead vocals. Generally, background vocals can get away with much more pitch correction than lead vocals before any artifacts are heard.
Depending upon how much of a purist you are, pitch correction is either the worst thing to ever happen or a godsend. Regardless of how you come down on the issue, it’s at the very least a necessary and powerful tool in today’s music. Use it wisely!
Bobby Owsinski is a producer and music technology consultant who is the author of 18 books about recording and the music business, including the most recent 3rd edition of The Mixing Engineer’s Handbook. Read his music marketing blog at Music 3.0 music industry blog, and his production blog at the Big Picture production blog. You can read about his books at bobbyowsinski.com, or follow him on Twitter for daily blog updates.