Use Pitch Correction reference tuning in Logic Pro for Mac
Turn on the Global Tuning button to use Logic Pro Tuning settings for the pitch correction process. This ensures that all software instruments and your tuned vocal part are in tune with each other.
If Global Tuning is turned off, you can use the Reference parameter to set the reference tuning to the root key or note.
As an example of where choosing a value with the Reference parameter can be effective, consider that the intonation of a vocal line is often slightly sharp or flat throughout an entire song. You can use the Reference parameter to address this issue at the input of the pitch-detection process by setting it to reflect the constant pitch deviation in cent values. This allows for more accurate pitch correction.
Note: Tunings that differ from software instrument tuning can be interesting when you want to individually correct the notes of singers in a choir. If all voices are individually and perfectly corrected to the same pitch, the choir effect is partially lost. You can prevent this by (de)tuning the pitch corrections individually.
Set Logic Pro reference tuning
In Logic Pro, choose File > Project Settings > Tuning to determine the tuning reference for all software instruments.