What does a creative director do?

‘What does a creative director do at a publishing house?’ he asked after we were introduced to each other at a party. That question was asked at several events I attended this weekend. At the party, I paused to consider general day to day tasks that consume me. Took a sip from the Belgian-style wheat ale we were enjoying and said, ‘A creative director is like an air traffic controller for an art department.’ As that metaphor seemed to resonate and take form in his mind I added, ‘An air traffic controller who often has to pilot the aircraft that is landing.’ That seemed to raise a few eyebrows.

I’d like to know how other creative directors define their role.