Owner`s manual
11
To take maximum advantage of the power of Auto-Tune Live’s pitch cor-
rection functions, you should have a basic understanding of pitch and how
Auto-Tune Live functions to correct pitch errors. This chapter presents basic
terminology and introduces Auto-Tune Live’s operating paradigm, giving
you the background you need to use it eectively.
A little bit about pitch
Pitch is traditionally associated with our perception of the “highness” or
“lowness” of a particular sound. Our perception of pitch ranges from the
very general (the high pitch of hissing steam, the low pitch of the rumble of
Godzilla’s enormous footsteps as he stomps his way through Tokyo) to the
very specific (the exact pitch of a solo singer or violinist). There is, of course,
a wide range of variation in the middle. A symphony orchestra playing a
scale in unison, for example, results in an extremely complex waveform, yet
you are still able to easily sense the pitch.
The vocalists and the solo instruments that Auto-Tune Live is designed to
process have a very clearly defined quality of pitch. The sound generating
mechanism of these sources is a vibrating element (vocal chords, a string,
an air column, etc.). The sound that is thus generated can be graphically
represented as a waveform (a graph of the sound’s pressure over time)
that is periodic. This means that each cycle of waveform repeats itself fairly
exactly, as in the periodic waveform shown in the diagram below:
Because of its periodic nature, this sound’s pitch can be easily identified and
processed by Auto-Tune Live.
Other sounds are more complex. This waveform:
is of a violin section playing a single note in unison. Our ears still sense a
specific pitch, but the waveform does not repeat itself. This waveform is
a summation of a number of individually periodic violins. The summation
is non-periodic because the individual violins are slightly out of tune with
respect to one another. Because of this lack of periodicity, Auto-Tune Live
would not be able to process this sound.