Some dogs got into treble recently at a stunt using their wagging tails to help conduct an orchestra — and got mixed reviews from the musicians. “They must be crazy,” said one (human) performer. The unusual composition was arranged by the Pedigree pet food company that posted a compilation video on YouTube that it said shows the experiment involving the Polish Radio Orchestra and a series of pooches presented with “different stimuli.” They included a chew toy that looked like a stalk of broccoli, a charcoal grill and what the company said were its dog treats — which apparently prompted some ve…