What is the relationship between songwriters, performers, and
recording companies as far as royalties and copyright/licensing are
concerned in creating music and records??

Hello there

This is a direct quote from a very clear article on the subject at 
"Music Publishing: How Your Songwriting Generates Income"
( http://www.legaljungleguide.com/resourc/musician/articles/songwriting.htm
)

"As a songwriter, you earn money by licensing your songs for various
uses, and collecting the corresponding license income. This process of
generating income from your songwriting is music publishing. To
understand music publishing, you should understand the distinction
between a song and a sound recording. You should also understand the
exclusive rights a copyright owner holds in his songs and sound
recordings. If you're a bit foggy on these issues, you might want to
review the article, What Exactly is A Music Copyright?.
( http://www.legaljungleguide.com/resourc/musician/articles/musiccopyright.htm
)

This second article goes on to explain copyright law, who holds what
rights etc etc

Back at the first article, it goes on to say: 

"The most significant revenue for the typical songwriter comes from
issuing the following licenses:

- Mechanical Licenses
- Performing Rights Licenses
- Synchronization Licenses
- Print Licenses
- Foreign Licenses

Then it goes on to run through each licence in turn.

The same site also maintains Music Business Resources with free
articles on how to register your copyright, how to negotiate with an
agent, and copyright law here:
( http://www.legaljungleguide.com/resource.htm )

Hope that helps you out

willie-ga

Google search used
musician rights glossary