Great 2005 interview with Dan Penn from Performing Songwriter magazine. It's available from their site (for a small fee) here:
http://performingsongwriter.com/articles-interviews/producers-engineers/dan-penn/
Here's a brief excerpt:
You worked at both Fame and American
Studios. What was the difference between
the Muscle Shoals and Memphis style
of recording?
I got to watch Chips Moman at American
for several years. He cut different from Rick
at Fame. Rick, not really knowing any better,
had to put together a lot of bands, because
people kept leaving. He had to take green
musicians and teach them how to play in the
studio. Which was not what was happening
in Memphis. They had a band that already
had been playing for years—Reggie Young,
Bobby Emmons, Gene Chrisman, all them
guys. They weren’t leaving. So in Alabama,
it was more or less Rick saying, “Don’t do
it that way.” He’d go out and take the guitar
and show them what to play. Maybe a little
bit uncouth, but he got his message across.
But in Memphis it was not that way at all.
Moman basically just sat there, and it looked
like he was praying. He had this look on
his face like, “I know it’s coming through
any time.” They’d go into take 42 in a New
York minute, because that band was so good
that they’d take a piece of crap—excuse my
English—they’d take any old song and hit
such a groove that the song actually started
sounding good. So I got to watch that band
and watch him work for several years, and
I’ve got a big dose of that in me. Chips didn’t
really get on the talkback a lot. In Alabama,
it was talk, talk, talk. A lot of communi-
cation, because nobody knew what the heck
they were doing (laughs). But in Memphis,
they’d done passed that stage, and they
were into, “Try that again.” Everybody in
the band knew what to do. I guess if I’m
anything, I’m a combination of those two
studios. Plus my own stupidity that I throw
in there with it (laughs).