Musical Chairs

“Ladies and gentlemen of the orchestra, be seated. Not so fast, says the conductor. Violins, you may take your places to my left, for the moment. Violas, let’s see. Should you be on my right, or should the cellos go there? Basses, let me think. Winds, brasses and percussion, you know where you need to be. (Or do you?)” These days, there seem to be as many orchestral seating configurations as there are conductors. But how do they decide where they want everyone to sit, and why does it matter?