Though I didn’t see Terry Teachout’s ominous look at the state of jazz in 2009 when it originally ran in the August 9 issue of the Wall Street Journal, in the week and a half since then it’s been hard to miss the hubbub the story has caused. Armed with statistics from a recent National Endowment for the Arts survey, Teachout describes jazz’s allegedly declining fortunes, with an emphasis on the aging of its audience and its lack of new listeners.