This is a really nice explanation of what a conductor contributes to an orchestra, written by a conductor himself.
The Mysterious Art of Conducting
Conducting—waving a wand to summon ravishing or ethereal or earsplitting sounds—can look like either inexplicable magic or embarrassing nonsense, @aucoincomposer, himself a conductor and composer, writes. He explores the profession's power and purpose:
theatlantic.com