In a February 2011 NEA Research Report, “Age and Arts Participation: A Case against Demographic Destiny” by Mark J. Stern, we find a refutation of the so-called dire data that is what the author is calling the “Demographic Destiny” of the graying of arts audience.  The description from the link to the reports above:

Mark Stern, University of Pennsylvania, analyzes the relationship between age and arts participation in the Survey of Public Participation in the Arts data for 1982, 1992, 2002, and 2008. The report concludes that age and year of birth are poor predictors of arts participation and that the age distribution of art-goers now generally mirrors that of the U.S. adult population.

Which is pretty much both Matthew Guerrieri and I surmised given a more nuanced look at the data.  Basically, the aging audiences is simply a function of Demographic Evolution rather than Demographic Destiny.