In 1935 Bush began work on a piano concerto which, completed in 1937, included the unusual feature of a mixed chorus and baritone soloist in the finale, singing a radical text by Randall Swingler. Bush played the piano part when the work was premiered by the BBC Symphony Orchestra under Sir Adrian Boult on 4 March 1938. The largely left-wing audience responded to the work enthusiastically; Tippett observed that "to counter the radical tendencies of the finale ... Boult forced the applause to end by unexpectedly performing the National Anthem". A performance of the concerto a year later, at the 1939 "Festival of Music for the People", drew caustic comments from Neville Cardus in "The Manchester Guardian". Cardus saw little direction and no humour in the music: "Why don't these people laugh at themselves now and then? Just for fun."