 For the course of the war Myra Hess , and other musicians , such as Moura Lympany , gave daily lunch @-@ time recitals in the empty building , to raise public morale at a time when every concert hall in London was closed . A number of art exhibitions were held at the Gallery as a complement to the recitals . The first of these was British Painting since Whistler in 1940 , organised by Lillian Browse , who also mounted the major joint retrospective Exhibition of Paintings by Sir William Nicholson and Jack B. Yeats held from 1 January – 15 March 1942 , which was seen by 10 @,@ 518 visitors . Exhibitions of work by war artists , including Paul Nash , Henry Moore and Stanley Spencer , were also held ; the War Artists ' Advisory Committee had been set up by Clark in order " to keep artists at work on any pretext " . In 1941 a request from an artist to see Rembrandt 's Portrait of Margaretha de Geer ( a new acquisition ) resulted in the " Picture of the Month " scheme , in which a single painting was removed from Manod and exhibited to the general public in the National Gallery each month . The art critic Herbert Read , writing that year , called the National Gallery " a defiant outpost of culture right in the middle of a bombed and shattered metropolis " . The paintings returned to Trafalgar Square in 1945 . 
