On Ukraine’s borders, in Moldova and Poland, refugees are swiftly pouring in, the biggest refugee crisis in Europe since 1945. In a night dedicated to aiding Ukraine through the charitable organizations Wonder Foundation and Katalyst, a diverse group of speakers and musicians are performing. The program begins with talks by the Putin expert Misha Glenny and the historian Sir Simon Schama and the actors Sinéad Cusack and Jeremy Irons, and follows with readings. Then the Cello Quartet will perform. —Elena Clavarino