"published" Music

It would probably depend on the individual policies of the place you were trying to have your work published.  Mainly, I would think they wouldn't want anyone making money off of your compositions other than themselves.  So they wouldn't want you to be simultaneously dealing with two different publishers for the same piece of music, or selling your compositions off your website and also through them.  

Given that the point of YC is to post scores for peer review by other composers, not for commercial gain, I don't really think it's very different from giving a copy to a friend and asking what they think of it.  We don't get a lot of music directors here looking for freely downloadable scores to perform.  It's just all of us in the composing community, listening to each others pieces.  Legal teams at the publishers may think differently though, so if you are at the level of approaching them for publication or applying to lots of competitions, it would be good to do your homework.  

But mainly, that would be a question for a contract you made for work you produce in the future.  It probably doesn't matter too much for work you've already produced.  If you currently worked with one publisher, and another wanted exclusive rights to your work, they would just pay you a little more than the last publisher and ask you to formally sever your old contract with your old publisher.  Who cares what you did last month, they just want to pay for the right to control your output going forward…  

(I'm guessing.)

Frankly, I'd ask some publishers.  Because I'm just guessing.  

No, and the same goes for any aspect of creative output. "Published" is a meaningless term in this sense. What you need to consider is who owns the intellectual property rights. If you share something on a website that explicitly states in it's terms of use that you forfeit the rights to your work upon upload then it isn't necessarily published as much as it is freely given away.

Most websites allow you to retain your intellectual property rights and as such you are still free to distribute it through some other channel if you find one to do so.

Whether or not a publisher would be interested in something is another issue altogether. Just because you'e never shown something to someone doesn't mean anyone will be interested in it anyway, and just because you share something online doesn't preclude you either.

Generally, if it's something that a publisher thinks they can make money off of, they will. That is just about the only criteria that any publishing house cares about.

As a side note though, don't worry about publishing houses. Obviously there are multiple outlets in the modern world for you to put your music out without having to give a third party a portion of whatever profits might be made. If anything, the UPS store is wonderful for helping you create professional looking scores. If you lack the skill, you can hire an engraver to make your scores look great, then you just print it off and get it bound. Find someone who wants to buy it, sell it to them yourself.

It is highly unlikely that a publishing house would be interested in you or that you could make any practical use of them anyway.

Thank you U238 for your detailed response the other day. A lot of clear intelligent sense there. I have posted in a couple of music forums and the general consensus seems to be 'not to worry too much' ... With literature people seem to warn against uploading an entire piece to a website. Not so with recordings of music.

Thanks again