The science of conducting?, and homage to Clive Granger

From The Economist:

DO ORCHESTRAL conductors do anything useful? Alessandro D’Ausilio of the Italian Institute of Technology, in Genoa, and his colleagues tried to answer that eternal question in a study published in the Public Library of Science.

And:

Each violinist had an infra-red reflector attached to the tip of his bow, and the conductors had them attached to their batons. Dr D’Ausilio and his team were thus able to follow the movements of both bows and batons by bathing their little orchestra in infra-red light, which their cameras could see, but human beings cannot. They then used the movements of the reflectors to analyse who was affecting whom.

To do this, Dr D’Ausilio employed a mathematical trick called the Granger causality test…

And the (tentative I would say) result:

The findings are in harmony with what conductors knew all along: that baton-toting despots, like the late Herbert von Karajan, do add value—but only if they rein in the uppity musicians in front of them.