What does a producer do? I'm serious, I've never been in
the presence of one at work and have no idea.

And neither do some producers. Thank you, thank you, here all week, try the
veal, tip the waitress.
But seriously, there isn't one template for what they do. Some just sit there
and direct the session by indirection, making a comment here and there, I like
that, don't like that, let's try another take, let's move on, and so on. I
call that the Lou Adler approach because that's what Lou does although he
doesn't produce many records anymore.Very low key and in Lou's case very
effective because he has great taste. BYW, Lou is the tall guy with the beard
sitting next to Nicholson at the Laker games.

Some producers arrange, write, tell the players what notes to play, very
involved in every aspect. Can work just as well. It all depends.
As an aside there is a documentary about Tom Dowd coming out about now that
should offer some insights on what some of the great producers of R&B do.
Phil Brown