Philadelphia’s prestigious Curtis Institute of Music has a new board chair. H.F. “Gerry” Lenfest, 75, will take over the leadership of the school’s board in June, just as Curtis is also welcoming new director Roberto Diaz. Lenfest, pne of the city’s most active arts supporters, donated $6 million to Curtis last year. He is also chairman of the Philadelphia Museum of Art and the American Revolution Center.