That's a very good summation of "snake oil" Julie and [if I can say so] free from bias. I haven't got any of the advanced knowledge of energy fields etc that others have [in fact last night's University Challenge Questions on electrical units had me baffled
]. In terms of transferring useful amounts of power wirelessly though I'd always thought that Tesla's aim was to utilise the planet's natural resonant frequency which has much higher current prospects and even in my ignorance, seems to make sense. Anyone can light up a flourescent tube! Soldiers in step over a bridge can destroy it and this factor is a also basic aspect of AC electrical distribution [I think]. If you get down to 8 or 9 cycles the human body is at risk of being micro-waved to death! I won't wander further into into music or Joshua and the Walls of Jericho
Dave W