With all of the attention these past few years on the Auto-Tune Vocal Effect (the T-Pain/Cher style effect) and its ubiquity in pop culture, it's easy to forget that Auto-Tune was initially designed (and is still most commonly used) for extremely realistic, natural-sounding pitch correction. Each new generation of Auto-Tune improves audio quality and ease of use; by taking advantage of the following techniques, it can be virtually impossible to hear that pitch correction has been applied.
The single most important Auto-Tune parameter for natural pitch correction is Retune Speed. This is the speed at which the pitches of any out-of-tune notes in the audio are changed to the "right" notes. The goal is to set a Retune Speed that's fast enough to get out-of-tune notes in tune quickly, but not so fast that you can hear it happening in an unnatural way. This is made trickier by the fact that the optimum Retune Speed for any performance depends on such attributes as song tempo, note duration, and vocal style, and can often change from note to note.
Luckily, Auto-Tune Evo includes unique tools in both Automatic and Graphical Modes to make it easy to set optimum Retune Speeds.
One situation that can be problematic in Automatic Mode is a performance that includes both very short notes and longer sustained notes. The problem is that in order to get the short notes in tune, you have to set a fast Retune Speed, which would then make any sustained notes sound unnaturally static. Fortunately, Auto-Tune Evo's Automatic Mode Humanize function easily solves this problem.
The Humanize function differentiates between short and sustained notes and lets you apply a slower Retune Speed just to the sustained notes. Thus, the short notes are in tune and the sustained notes still allow the natural variations of the original performance.
Here's how it works:
Start by setting Humanize to 0 and adjusting the Retune Speed until the shortest problem notes in the performance are in tune. At this point, any sustained notes may sound unnaturally static. If so, start advancing the Humanize control. The higher the Humanize setting, the more the Retune Speed is slowed for sustained notes. The goal is to find the point where the sustained notes are also in tune and just enough of the natural variation in the performance is present in the sustained notes to sound natural and realistic. (If you set Humanize too high, any problematic sustained notes may not be fully corrected.)
Prior to Auto-Tune Evo, it was necessary to select a single Graphical Mode Retune Speed that applied to all of your pitch corrections. Your choice was typically picking a Retune Speed that was a "good enough" compromise for an entire track, or painstakingly automating the Retune Speed from phrase to phrase or even note to note (with the attendant cost in time and effort).
With Auto-Tune Evo, Antares has introduced the ability to set independent Retune Speeds for every individual correction object, whether Line, Curve, or Note. Simply select one or more objects and set the Retune Speed that provides the most natural result. Getting exactly the desired effect for every note of a performance is a quick, simple, and intuitive process.
Of course, in practice you don't need to set an individual Retune Speed for every object. To streamline the process, start by selecting all your audio and setting a Retune Speed that works for the majority of the performance. Then listen to the result and note which notes or phrases could still use improvement. Select those notes or phrases, adjust their Retune Speeds for the most natural result, and you're done.
With independent Retune Speeds for each correction object, Auto-Tune Evo includes the time-saving ability to set custom default Retune Speeds for each of the three object types: Lines, Curves and Notes. These are the initial Retune Speed values that are automatically assigned to each newly created object.
To choose your own values, just pay attention to what values you most commonly use for the various objects and set those as defaults in Auto-Tune Evo's Option dialog. Update as necessary.
Of course, it's possible to make Auto-Tune Evo do the obvious type of 'hard' correction effects you hear on so many hits these days. But don't forget that it's also a tool for doing transparent, non-obvious correction that can help save a session.
Copyright 2010 by Antares Audio Technologies and adapted for Harmony Central with the express written consent of the publisher. For more information on Antares and Auto-Tune Evo, visit www.antarestech.com