Apple Logic Express 9 - Manual (Page 1185)

The positions of individual notes in each chord are analyzed, and the sum of each note’s
distance to the tempered tuning scale is zeroed. In critical cases, different compensation
functions help to minimize the degree of retuning, at the expense of absolute purity, if
necessary.
For example:
• The notes C, E, and G form a C Major chord.
• To harmonically tune these, the third (the E) needs to be tuned 14 cents higher (a cent
is 1/100th of a tempered semitone) and the fifth (the G), needs to be 2 cents higher.
It should be noted that Hermode Tuning is dynamic, not static. It is continuously adjusted
in accordance with the musical content. This is done because, as an alternative to
tempered, or normal, tuning, fifth and third intervals can also be tuned to ideal frequency
ratios: the fifth to a ratio of 3:2, the major third to 5:4. Major triads will then sound strong.
With clean (scaled) tuning, Hermode Tuning changes the frequencies to values that are
partly higher or partly lower.
1185 Chapter 42 Project Settings in Logic Express