Originally Posted by mbriant
I know they're important because every orchestra has one and they always seem to take top billing, but exactly what is it that they contribute? Timing? The "waving the stick around" part we laymen always see, obviously isn't all of it, but is it the most important contribution they make?
The best analogy I can think of is the director of a play. The director puts his stamp on everything. He works with each of the actors to set the tone and mood of the play. By directing the individuals, the interaction between the actors is shaped and the emphasis of the entire play can change completely. The director changes the pacing and even the script when warranted. There are countless ways the director can change the feel of a play.
If you've seen multiple performances of the same Shakespearian play, you know how each can be totally different depending upon the direction (not to mention acting). The script may be identical, but one performance can be heavy and maudlin while another crisp and fresh. Conducting can produce similar results.