BAM Audio School
Home
Course Index
Sign Up
Virtual Mixing
Processing

HARMONIZING / PITCH SHIFTING / AUTOTUNE


A harmonizer can change the pitch (tone) or a sound.  It can make a low sound high or vice versa.  A harmonizer can be changed while a sound is playing through it, allowing you to “play” the pitch of any track.  Harmonizers have long been used to fix the pitch of instruments and vocals, or to create unusual sounds by making an instrument higher or lower than usual. 

Computer Harmonizers that operate in real time work by playing back the sound at a slightly different sample rate that it was recorded at (which speeds up or slows down the sound wave frequency, which changes musical pitch).   Stand-alone boxes such as the Eventide Harmonizer work by first sampling sound that comes in through the analog inputs, then very quickly playing the sound back at a different sample rate, or speed.  Of course all of this processing causes a delay in the sound that sometimes required compensation.

AUTOTUNE is an audio process that samples everything that goes in, analyzes the frequency (and musical pitch) of the sound, then alters the playback sample frequency so that the resulting changed frequency (and musical pitch) hits a specific note.  You can use subtle or extreme settings.  Slow settings will be more natural, while fast settings will result in jumps (especially if the target notes are far apart from each other and even the original note).  These fast jumps were first heard on Cher’s song “Believe”, but have become known as the “T-Pain” sound.