The precipitate decline of a hybrid American art form continues. In the 2014 annual stats from Nielsen, just out, jazz accounted for just 1.4 percent of music sales – exactly the same as classical music but falling faster. Three years ago, jazz commanded 2.8 percent of the market with 11 million album sales. In 2014, just 5.2 million jazz albums changed hands. Classical, by contrast, held steady – albeit at a historic low ebb.