Are electric guitars essential to metal?

Electric guitars and distortion are an integral part of the metal idiom, the most readily apparent source of idenity, but as Dreamlord and Erik indicate, the essential spirit that defines metal may not be dependent upon their use. As for whether one can break completely from the genre in terms of sound yet retain compositional techniques associated with metal, I'm sure it can be done with satisfying results...
 
I believe metal has evolved and expanded so much that "extreme music" is a more relevant term. A Blind Guardian fan would argue that Isis isn't metal, because they don't have solos and the singer uses a somewhat hardcorish vocal style. But if you go back to my thread about why Watchmaker and Goatsblood are more metal than Arch Enemy and Zyklon, this would also apply to Isis being more metal than Blind Guardian . . . by far.

What I'm saying is that metal has always represented music that rebels against the popular form of rock or metal at that time. Something could be metal without electric guitars simply because it rebels against black metal in general . . . but that doesn't mean it has anything to do with rock music. Kvledssanger is a sort of rebellion against all the blasting black metal of that time. It is also just another step in the Ulver trilogy, but I think it was meant as more of a statement of "what makes metal metal".

I'm going to record an album of nothing but insanely Satanic farting noises. It will be called 'Metal Out The Ass!', and it will be so metal it will hurt.
 
I will be first in line for that album. :)

I understand the rebellion bit, but if you heard Kveldssanger for the first time without being acquainted with what Ulver was (at the time), would it still be considered metal? I listen to that album and picture Norwegian hippies sitting 'round a campfire singing folk songs. Just because they happened to record black metal albums before and after it does not make that particular release metal. Just as I do not find their later material grounded in metal whatsoever.

When it comes to song structure, there are so many different varieties out there that it's hard to make a case. As npearce pointed out, the divergent sounds between pop-style songwriting like Arch Enemy are wholly different from a group like Goatsblood, but both fall under the metal umbrella.

It all comes down to distortion for me, but metal is what you make of it. :)
 
eh, whatever happened to just liking metal for what it was? There's no need to quantify how "rebellious" a piece of music is just because at the end of the day, all you need to do is press 'play', and if you like what you hear, don't press 'stop'. When did it listening to music, reading a book, watching a movie etc turn into a mission statement?

Somebody once said that Metal is about Blood, Fire, and Death. We all interpret that in different ways, but otherwise, the whole concept of its entertainment value doesn't need to go much further than that.
 
There's a jazz-fusion group from the 70's called Mahavishnu Orchestra. They are pretty much legendary. Anyway, they used very heavy distrotion and double bass drums before any heavy metal group. What's up with that? Are they metal? They also use the most complex time signatures humanly possible.