WebMay 14, 2024 · Gustav Mahler. Austrian composer. Written by. Deryck V. Cooke. Musicologist. Music Presentation Editor, British Broadcasting Corporation, London, 1965–76. Author of Mahler, 1860–1911. Completed Mahler's unfinished 10th Symphony. Deryck V. Cooke. Fact-checked by. The Editors of Encyclopaedia Britannica.