In late 2020, as coronavirus infections surged and cultural institutions shuttered, the fate of the long-delayed renovation of David Geffen Hall, the home of the New York Philharmonic, was uncertain. Then came a $50 million gift from Joseph Tsai, a Taiwanese-born billionaire co-founder of the Chinese e-commerce giant Alibaba Group, and his wife, Clara Wu Tsai, a philanthropist. The donation moved the project forward, accelerating construction so the hall could reopen in October, a year and a half ahead of schedule.