As one of the first U.S. cities to create a fund for artists devastated by the ongoing coronavirus shutdown, Denver has received national attention and praise. But the city’s collective efforts, which have amounted to hundreds of thousands of dollars for the most vulnerable organizations and artists, quickly proved to be a drop in the proverbial bucket of sorrows now collecting at most nonprofit cultural institutions. “Our goal is to raise $40,000 between now and July 31,” said Sarah Gumina, spokeswoman for the Rocky Mountain Arts Association, which is predicting a $75,000 deficit for its 2019-2020 season of vocal concerts.