why do sites such as the musicians answering service web site come up
when I do a simple search on "answering service", yet other sites
don't come up until much later that have more relevance to answering
service?

Dear Gigi,

It is sometimes difficult to tell, why certain sites have better
"ranking" than others, or why they appear on the first results, why
others - which may better suit you - appear only on later results.

In order to understand that, you have to understand how the Google
ranking system works.

You could read this page, in order to know more about how Google ranks
its results:
"Our Search: Google Technology"
<://www.google.com/technology/index.html> 

Basically, links and importance of the page are the indicators of
ranking: if you are linked to many "quality" ("important") sites,
you'll get a higher rank than sites that are linked to less important
sites or not linked at all.

This could have happened with certain sites, that may not seem
"important" to you, but to many who are interested in this industry,
are; and have also many quality links. For example, the Musician
Answering Service might be linked to music resources directories,
music related sites, etc. - and not only to messaging services.

Naturally, there could be a case where someone tried to "hack" Google,
inserting a site with no relevant content, and with no quality links,
into the first results, by spamming the search engine. If you suspect
such a thing, you could report it to:
<://www.google.com/contact/spamreport.html>. 

In addition, in the case of the query "answering service"
<://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22answering+service%22>
you have several meaning of this term (for example: services like
Google Answers, that provide answers to questions; services in which
secretaries take messages - "answer" - by telephone; etc.). Sometimes,
it might be helpful to add more search terms that might enhance your
search terms, or to use the directory
<://www.google.com/webhp?hl=en>.

See Google Search explanations
<://www.google.com/help/basics.html> 

I hope this answered your question. Please contact me if you need any
further clarifications on this answer before you rate it.

Or why does Google Answers appear in the results?

gigi2698-ga,

It's deifficult to say with certainty why any particular result is
given the ranking it has. Some webmasters are guilty of practices that
favor search engine positioning but which compromise relevance, such
as reciprocal link schemes, hidden keywords, misleading meta tags,
etc.

omniscientbeing-ga