Er, well Slayer isn't "Black Metal", it's thrash or speed metal. Black Metal would be stuff like Mayhem, Immortal, Emperor, Burzum etc. (although some may categorize Satanic themed material as "black metal", although the music is much different than what the Norwegians created) Anyway, technicalities aside you are correct, at first listen some metal music will be competely overwhelming. This is also the same 'aurally assaulting' attribute that makes people fans of it. Still, anyone with a musical background should be able to hear through the 'noise' and be able to ackknowledge the skill, dexterity and sheer stamina it must take to play this stuff. Cripes, try air-drumming along with Dave Lombardo sometime - you arms will turn into mush before one song's over! Heh! And many bands have awesome, clever, intelligent lyrics if you care to read them.
The power cords? Top secret recepie - if I told you I'd have to kill you. No seriously, for the 5-way there's six strands of 18AWG silver-plated copper in a teflon jacket twisted into tight pairs with a drill motor and then I hand-braided the three pairs together for each plug. Then the five braids were braided into one big braid, plugs were terminated, shrink tube added, tested with a multi-meter for continuity and bob's your uncle. A good week or two on and off of work for the sole purpose of saving myself four spots on the 'ol power strip. Not a project I care to repeat anytime soon!
Jackman bought a pair of my interconnects, which are the best cables he's ever used. I'm looking forward to his review. Not everyone will be able to afford them, as they are true reference level stuff. There are built-in gaps where up to 47 wire staples may be attached to the optional sheet of Sorbothane-impregnated HDF hybrid material which must be terminated to the earth's mantle using the provided deep drilling rig and concrete pillars.