In 1989, he and his wife, Vivian Ge, an accordion player whom he met in the labor camp, founded a business, now called Peony Online, which provides information on the market for metals. “I thought in six months I’d be rich and go back to composing,” he said, adding, “I was not really interested in business, but if I do one thing I try to finish it.” After the company became successful, Mr. Ge began composing again full time around 2000.