A US orchestra has held its most unusual performance - being conducted by a robot. The Detroit Symphony was led by Asimo, a 1.3 metre (4ft 3in) tall robot designed by car manufacturer Honda as it performed The Impossible Dream. Asimo was programmed to mimic the orchestra's education director as he conducted the piece in front of a pianist six months ago. But the robot cannot respond to the musicians' actions. So during early rehearsals, Asimo - which stands for Advanced Step In Innovative Mobility - slowed the tempo and the orchestra lost its place, something a human would have sensed. "It's not a communicative device, it simply is programmed to do a set of gestures," musical director Leonard Slatkin said. Bassist Larry Hutchinson said while the movements were a little stiff, they were "very humanlike, much more fluid than I thought".