With the Correction control set to zero the result is a constant pitch change.
Full correction may remove expression or vibrato.
The 'expected' pitch can be controlled by MIDI, or be a fixed set of notes.
So it should be used to correct small errors only and not to really transpose a song.ĪT1 can probably be used on some instruments as well, but is primarily designed to cover the vocal range. It works by resampling and looping the signal and does not include formant correction, X42-autotune (aka fat1.lv2) is an auto-tuner based on Fons Adriaensen'sĪT1 is intended to correct the pitch of a voice singing (slightly) out of tune.