It’s not a good time for the arts in America, with budget cuts, looming deficits, and dwindling audiences seemingly national problems. But somehow, the Spoleto USA festival, based in South Carolina, keeps chugging healthily along, balancing its books and keeping its considerable audience happy with innovative presentations and high-quality music. “Last year’s festival set a box-office record, with ticket sales totaling slightly more than $2.5 million. The festival recently concluded a $26 million fund-raising drive that, among other things, increased its endowment fund from $600,000 to $7 million.” Among the highlights being planned for next year’s Spoleto: a full performance of an 18-hour opera from 16th-century China.