- The word "conductor" has another meaning in Electrical Engineering— a substance that conducts electricity well, or an object (e.g. a wire) that exploits this property.
A conductor is a person who leads an orchestra. Originally the person responsible for keeping time in an orchestra was not an older instrumentalist, usually a percussionist, who could no longer play his instrument at a high level. As music got more complicated, conductors became responsible for more things. Conductors usually direct the music in terms of dynamics and volume balance between instruments or between passages.
Famous conductors, past and present, include Daniel Barenboim, Riccardo Chailly, Seiji Ozawa, Arturo Toscanini, Bruno Walter, George Szell, Giuseppe Sinopoli, Sir Georg Solti, Sir Neville Mariner, and Sir Charles Mackerras.