Here’s the simple response: When an orchestra plays behind the conductor, it has the room to produce a more expressive sound. “It works so well because the musicians can take in a great deal more information before they play,” said Falletta. Waiting a tick allows the ensemble to take in the trajectory, speed and style of a conductor’s beat, which helps them determine what kind of sound the conductor is hoping to achieve. “It gives them a chance to prepare that sound. So the downbeat comes, and the sound opens after that.”