Breaking Conductors" Down by Gesture and Body Part A composite of images of Alan Gilbert, music director of the New York Philharmonic, as recorded by computer in a motion-capture sequence. ARMS carve the air. A hand closes as if to pull taffy. An index finger shoots out. The torso leans in, leans back. And somehow, music pours forth - precisely coordinated and emotionally expressive - in response to this mysterious podium dance. Concertgoers, who train their ears on the orchestra, inevitably fix their eyes on the conductor. But even the most experienced listener may not be aware of the subtle and deep connection between a conductor's symphony of movements and the music emanating from the players. So in an attempt to understand what is going on, we interviewed seven conductors as they passed through New York in recent seasons with an eye to breaking them down into body parts - like that poster in the butcher shop with dotted lines to show the different cuts of meat - left hand, right hand, face, eyes, lungs and, most elusive, brain. The conductor's fundamental goal is to bring a written score to life, through study, personality and musical formation. But he or she makes music's meaning clear through body motion. "If you imagine trying to talk to somebody in a totally foreign language, and you wanted to express something to that person without the use of language, how would you do that?" the British conductor Harry Bicket said. That's really what you're doing. Every baseball pitcher has a different motion, but all pitchers want to retire the batter. Similarly, every conductor employs a singular style, but all want to elicit as great a performance as possible. So our breakdown has inherent generalizations. In the end it must be remembered that the art of conducting is more than just semaphore. It is a two-step between body and soul, between physical gesture and musical personality. The greatest technician can produce flabby performances. The most inscrutable stick waver can produce transcendence. "You can do everything right and be of no interest at all," said James Conlon, the music director of the Los Angeles Opera. And you can be baffling and effective. Traditionally (for right-handers, at least), the right hand holds the baton and keeps the beat. It controls tempo - faster here, slower there - and indicates how many beats occur in a measure. The baton usually signals the beginning of a measure with a downward motion (the downbeat). An upward movement prepares for the downbeat. Conducting manuals say the upbeat and downbeat should take the same amount of time, and that interval should equal the length of the beat. "The upbeat is the preparation for any event," said Alan Gilbert, the music director of the New York Philharmonic. Setting the right tempo for a musical passage is critical. No less an authority than the composer Richard Wagner, also one of the first modern conductors, said the "whole duty of a conductor is comprised in his ability always to indicate the right tempo." Yet a conductor is not a black-coat-and-tails-wearing metronome. "One of the big misconceptions of what conductors do is they stand there and beat time," Mr. Bicket said. Most orchestras don't need anyone to keep time. But the baton can also shape the sound. The nature of the downbeat - how abrupt, how delicate - tells the orchestra what kind of sound character to produce. The baton can smooth out choppy phrases by moving through the beat in a more sweeping way. A more horizontal motion can create a more lyrical quality, said James DePreist, the former director of orchestral and conducting studies at the Juilliard School. A downward stroke that imitates a violin bowing movement, Mr. Bicket said, can color the attack. Even when beating time through long-held notes, Mr. Gilbert said, the conductor should be trying to communicate the sound quality through the movement of the baton. A predecessor of Mr. DePreist's at Juilliard, the conducting master Jean Morel, taught that the right hand and wrist should be "thoroughly self-sufficient," said Mr. Conlon, a Morel student; it should "do everything - time, expression, articulation, character - so that you could then apply the left hand and withhold it at will." Xian Zhang, a master of sculpturing musical line with her baton, demonstrated this while rehearsing Mozart's Sinfonia Concertante for Violin and Viola with a student orchestra at the Juilliard School. Her stick movement closely matched the music's character, turning delicate for gentle passages, small for accompanying strings, larger for a horn and oboe melody. Her arm strokes grew broad at vigorous lines. Sometimes the uplift of her baton seemed literally to draw out the sounds. Some conductors prefer at times, or all the time, not to use a baton. Yannick Nézet-Séguin, who becomes the music director of the Philadelphia Orchestra in September, is one. His training came mostly with choirs, for which batons are rarely used. "Basically the hands are there to describe a certain space of the sound and to shape that imaginary material," Mr. Nézet-Séguin said. That imaginary body of sound sits in front of the conductor, between the chest and the hands, he added. It's easier when there is nothing in one hand. He started using a baton when he began guest-conducting at major orchestras, because they were more used to it.