When war broke out in September 1939, Bush registered for military service under the National Service (Armed Forces) Act of 1939. He was not called up immediately, and continued his musical life, helping to form the WMA Singers to replace the now-defunct LLCU, and founding the William Morris Music Society. In April 1940 he conducted a Queen's Hall concert of music by Soviet composers which included the British premieres of Shostakovich's Fifth Symphony, and Khatchaturian's Piano Concerto. William Glock in "The Observer" was disdainful, dismissing the Khatachurian concerto as "sixth-rate", and criticising the inordinate length, as he saw it, of the symphony.