That's pretty cool!.
I've seen the effects of the wrong frequency on a power system first-hand.
Our NZ (SI) members may remember back in 1992, when there was a problem at one of the Tekapo (I think) power stations and one of the alternators began what's known as "hunting" (speeding up and slowing down wildly).
Reason I say South Island only is because any power sent to the north is rectified into DC first.
This hunting effect caused a really eerie pulsing of the lights in peoples houses and caused quite a few problems with TV's and the like.
The pulsing was quite noticeable and so I'm told, Power companies recieved thousands of calls from concerned consumers.
Just goes to show what can happen when you have one errant alternator in a system.
And so I've learned since, it takes quite a bit of effort to get the alternator settled back into a steady speed again too.
Would have been interesting being a fly on the wall in the control room that night!.