Anatomy of a tuning plugin

Broadly, there are two categories of plugin tools that are most associated with vocal processing. Firstly, we have the post-production effects we turn to when processing any sound, such as EQ and compression. Yes, it’s certainly the case that processors like de-essers offer a bespoke approach to frequency-related dynamics control, which have been developed for vocals foremost. But generally, vocals require the same considerations – and effects – as any other sound.

However, certain tools fall outside this category, like plugins such as Celemony’s Melodyne and Antares’ Auto-Tune. In truth, while both can process non-vocal sounds, their extraordinary capabilities were first designed for voices. These plugins have become so popular that they have shaped the plugin-buying landscape, almost a ‘chicken and egg’ situation: producers lapping up the functionality Melodyne provides, for example, but then the manufacturers added features as the sounds they originated evolved.

So what do plugins like this let you do? Understandably, both Melodyne and Auto-Tune are known best as tuning plugins, designed to reduce or eradicate errors in tuning. Not only does this summary hugely underestimate the power of both programmes, it’s also too simplistic, as ‘tuning’ in itself is a complex concept. What both programmes allow for is a note’s central pitch and the amount of pitch modulation (vibrato) to be controlled separately. Often, it’s the second of these parameters which will determine whether a note sounds in or out of tune; wild vibrato is so distracting that even if the core note is ‘in tune’, the pitch base is knocked too far off kilter for that to matter. In that instance, reducing the width of pitch modulation will produce the desired result and, interestingly, it’s reducing this completely (no vibrato) which produces the hyper-tuned effect we know so well from the last two decades of pop music.

So, pitch-correction plugins can alter both the base pitch of a note and also the amount of pitch modulation independently but they go further still. Often a singer’s timing will require adjustment, either to pull a note forwards or backwards, to make it ‘sit’ alongside the rhythm of your track. Equally, sometimes some notes in a phrase will be in time, while others will be out of time, requiring careful manipulation of start points of some notes, while retaining the positioning of others.

Both of these approaches are possible, as is the artificial extension of a note which has ended too abruptly. This is often particularly useful at the end of a phrase, where a singer is running out of air and can’t quite make that final note last as long as it should. So, let’s suppose a note is fundamentally in tune and that its pitch modulation is also under control. That doesn’t necessarily mean that its tuning will sound right, as the way that the pitch of any note is approached is also hugely important. As singers move from one note to the next, they can slide (using a musical approach known as portamento or glissando), rather than jump between pitches as a piano player would. If this glide is too long or too short, it’ll sound unnatural, so having control over this parameter is also highly useful.

Finally, as we’re exploring in a separate boxout (and in video form this month), manipulation of a vocal’s formants provides creative options aplenty. Mastering all of these parameters, to understand how they can benefit your vocal recordings, is key to great-sounding results.

Generally, vocals require the same considerations – and effects – as any other sound