Metallica on the TV show "Timewarp"

I just saw a commercial for timewarp and they will be pointing their cameras at Metallica in action. Could be pretty cool. I am hoping to see some harmonics being played.

Did anyone else watch this? It was decent.

I never knew (and apologize if its in a lesson somewhere and I missed it) that octave notes are either 1/2 or twice the frequency of each-other.