Please can you tell me who is the host for the newsgroup
rec.music.dylan? I want to ask them to bar someone who is posting
inappropriate, abusive, distressing posts. Or tell me how to find out
who the host is, for myself. The posts are up on Google Groups so
surely you have some responsibility!

bill1234..

Thanks for your question regarding the rec.music.dylan newsgroup. 
rec.music.dylan is what is known as an unmoderated newsgroup.  This
basically means that nobody is "in charge" of the group.  A moderated
group has someone who is known as a moderator who filters through
messages and posts the approved messages to the newsgroup.  Google has
nothing to do with the postings in the various groups.  From the
Google Groups Help, http://groups.google.com/googlegroups/help.html :
"By its very nature, Usenet consists of information posted by many
people. Google does not monitor or control the content of this
information. Instead, we simply provide access to the public forum in
which people post their comments."

In reading through some of the posts in the newsgroup, I can see why
you are concerned.  The off-topic threads are something that occurs
within newsgroups all the time and the dedicated readers and posters
are the ones that are truly hurt by it.  A recommendation I would make
would be to get a newsgroup reader that has filtering capabilities. 
By using this filters, you can "block out" postings from specific
individuals.  You can see a list of the various newsgroup readers for
Windows at http://directory.google.com/Top/Computers/Software/Internet/Clients/Usenet/Windows/

For Macs at http://directory.google.com/Top/Computers/Software/Internet/Clients/Usenet/Macintosh/

Or, if you are using Outlook Express, you can set up filters there as
well.

Another option you may want to consider is starting your own moderated
newsgroup and invite the dedicated users of rec.music.dylan to begin
using that one.  In order to create a newsgroup, follow the steps
provided here:
http://www.faqs.org/faqs/usenet/creating-newsgroups/part1/

Thanks again for your question and I hope the above information has
been helpful.  If you need any additional clarification, please let me
know prior to rating my answer.

Regards,

-THV

Search Strategy:
rec.music.dylan

References:
FAQ: rec.music.dylan Frequently Asked Questions (1 of 2)
http://www.faqs.org/faqs/music/dylan-faq/part1/