In my last online class I had a question about the "Show Frequency" button at the bottom of the "Freq.Bands" menu. I asked Tom Collura for a little help on this one, and here is his answer:

"Freq:" shows the dominant frequency which is the "center
of mass" of the energy in the FFT. It is similar to a peak
frequency, but it considers the whole peak, not just
the "top". In principle, if you took all the energy in the
bin (e.g. 8-12 Hz) and tried to "balance" it on a pinhead,
that point is where the energy would be centered. So it
is an average of a type, and considers all the energy
in each component.

As a result, it is more accurate than a simple peak which
would simply "pick" a bin, and be good to 1.0 Hz. Our
dominant frequency calculation is good to 0.1 Hz, and
is very repeatable.

Tom