Well, I mean, somethings are more worth being expressed.  Even "accidentally".  And if something has more meaning, then it's more effective, those examples carry relatively little meaning.  Additionally, I'm sure many other things would be effective at conveying the meaning you get from those arts, making that art "better".

Also, I meant it's value to the audience.  I guess it's fair to say that it's overall value is higher if the art/meaning/impact isn't accidental.

Well I think any accidental subtlety is just as valuable as intentional subtlety, I'm not saying that we shouldn't look for the subtleties in the art's impact/meaning/emotions.  To base a working definition of off what earl chip said, "art's value can be judged by HOW WELL it achieves SOMETHING (including subtleties involved, whether intentional or accidental)"  There's a great deal of subtlety that can be achieved with just sound, and certainly A GREAT DEAL of art music which involves subtleties in sound alone.

Maybe I should've been more clear with the "I don't know how people think about art" comment, but that's certainly not coming from a place of ignorance, rather than the fact that it's impossible to know how everyone thinks about art, only the people thinking about art around me.  And considering I'm studying art (music composition) at the university level (and my composition teacher studied with Nadia Boulanger), I would like to think that I'm more informed on the subject than a lot of plumber dads.  Additional, I'm pretty sure that I'm not the only person who holds this kind of opnion about art from conversations with other composers and artists that I've had, but I haven't POLLED people so I dunno.

As for your line about Shoenberg and Cage, I definitely agree that context and place in arts history do matter in determining the value of the artwork.  As the value of a message of an art is less if it's a kitsch or cliche idea.  Unfortunately if you try to view Noise music and Industrial noise music like a lot of these artists along side such music and Shoenberg's or Cage's, then you'll find it's valueless.  Because, as someone said earlier, this is non-music (not all of it is really though), and certainly by the very nature such music is rejecting normal musical value, and maybe even philosophical value in some cases.  It's really anti-art, art about the lack of art.

And I don't really think it matters whether that's purposeful or accidental, either way it's the same non-music.  I feel art should be judged based on the merits of the piece of artwork itself, not what the artist wanted to do and whether that was achieved or not.  Granted this knowledge might improve your enjoyment of the artwork, but I don't think that the artwork is devalued by intentionality or accidentality.

I don't think that's what makes it valuable for me.  It's the emotional impact that makes me enjoy abrasive noise, and solely the emotional impact.  Also sometimes there are interesting shifts in timbre depending on what noise it is.

'art's value can be judged by how well it achieves its intent' is still bad but I'm not sure if anyone here is actually saying that or what. actually it seemed like headphonics was saying that value can be dermined BY its intent at first, but I didn't read the rest of his posts

nah thats not what im saying buuuut i think you need to factor intent in if you ARE going to judge it/its value or more than HOW MUCH YOU LIKE IT PERSONALLY but i'll elaborate later maybe

Actually I changed my mind, Intention CAN matter is some situations, but I don't think it always matters.