I wonder how many generators it took...
I heard that when you plug a Hammond organ into a generator, that it can go out of tune because the Hammond organ relies on a steady current to keep it in tune.
And so I thought that they all tuned to the Hammond because the power wasen't steady and the Hammond itself can't be tuned. But then I remembered that tuning a piano can be a bitch...
The film dubbing speed thing sounds plausible.