I remember, a good few years back now, an advert for asthma medication in some of my medical journals, which featured a young man playing the clarinet. Unfortunately he had his hands the wrong way round - right on the top keys, left on the bottom ones! I first checked with my clarinet-playing daughter that this was wrong, then I pointed this out to the company: they very kindly sent me a CD of Emma Johnson playing various clarinet concertos. (Or do they make left-handed clarinets?)