Karl Wilson Gehrkens, Essentials in Conducting
“ One member of a group is radiant with happiness, and very soon the others catch the infection and are smiling also; a singer at a public performance strains to get a high tone, and instinctively our faces pucker up and our throat muscles become tense, in sympathetic but entirely unconscious imitation. In very much the same way in conducting, the leader sets the tempo,—and is imitated by the musicians under him; he feels a certain emotional thrill in response to the composer's message,—and arouses a similar thrill in the performers ”
