Otto Klemperer conducting Mahler's 9th Symphony. The concert started very late! He eventually appeared, supported 2 men, one on each side - very slowly he staggered up the steps to the podium and was 'dumped'  into a chair. He raised his baton and the concert started. Unforgettable - a wonderful performance (Philharmonia?) - but how they followed his 'beat' I don't know. But they played their hearts out in response to his waving, quivering arms and hands. Terrific applause, when his arms flopped down to his side. He was escorted out, never to be seen again, despite continuing applause!