Mattila appears regularly in the major opera houses worldwide, including the Metropolitan Opera, the Royal Opera House in London, Théâtre du Châtelet, Opéra Bastille, the Lyric Opera of Chicago, San Francisco Opera, Houston Grand Opera, Vienna State Opera, Toronto Roy Thomson Hall and Großes Festspielhaus, Salzburg and with top orchestras.
Over his 30 years as a performer, Mr. Katz has accompanied such stars as Marilyn Horne, Cecilia Bartoli, Kathleen Battle, Kiri Te Kanawa, Sylvia McNair, Frederica von Stade, Karita Mattila, David Daniels, and José Carreras.