Well-known Australian classical performers include: sopranos Dame Joan Sutherland, Dame Joan Hammond, Joan Carden, Yvonne Kenny, and Emma Matthews; pianists Roger Woodward, Eileen Joyce, Geoffrey Tozer, Leslie Howard and Ian Munro; guitarists John Williams and Slava Grigoryan; horn player Barry Tuckwell; oboist Diana Doherty; violinists Richard Tognetti and Elizabeth Wallfisch; cellist David Pereira; orchestras including the Sydney Symphony Orchestra, the Melbourne Symphony Orchestra, the Australian Chamber Orchestra and the Australian Brandenburg Orchestra; and conductors Sir Charles Mackerras, and Simone Young. Indigenous performers like didgeridoo-player William Barton and immigrant musicians like Egyptian-born oud virtuoso Joseph Tawadros have stimulated interest in their own music traditions and have also collaborated with other musicians and ensembles, both in Australia and internationally.