BTW, the "pretty" sparks are little bits of burning metal launched by a momentary high current through a narrow bit of conductor (which is why they're easy to do pyrotechnically - just burn some metal particles!) , possibly with some arcing through the higher-conductivity metal vapor. Pure electrical sparks (of the 3kV/mm type) are a different thing entirely.
(The Electronic flash is about 350V, and nearly-lethal energy. Short the cap (carefully) and you get the first type of sparks. The flash itself is more the second type (but specialized, cause ionized Xenon and stuff.)) Sparks are actually rather complicated things...