 Gustav Mahler's 1906 Symphony No.8, for example, has been performed with over 150 instrumentalists and choirs of over 400.New woodwind instruments were added, such as the contrabassoon, bass clarinet and piccolo and new percussion instruments were added, including xylophones, snare drums, celestas (a bell-like keyboard instrument), bells, and triangles, large orchestral harps, and even wind machines for sound effects.