Ewing began his career in early music, performing under such conductors as William Christie, Paul McCreesh, Marc Minkowski and Roger Norrington. He has sung for opera companies including English National Opera, Welsh National Opera, Dutch National Opera, Opera national du Rhin, Zurich Opera, Berlin State Opera, Opera National de Lorraine, Nancy, and Opera Colorado, in Karlsruhe, Strasbourg and Lille and at the Salzburg, Aix-en-Provence, Aldeburgh and Lucerne festivals. 　　Ewing's operatic repertory includes Seneca (L’incoronazione di Poppea), Osmin (Die Entfuhrung aus dem Serail), Leporello (Don Giovanni), Sarastro (Die Zauberfl?te), Rocco (Fidelio), Sparafucile (Rigoletto), Heinrich I (Lohengrin), Fafner (Das Rheingold and Siegfried), Baron Ochs (Der Rosenkavalier), Kutuzov (War and Peace), Bluebeard (Duke Bluebeard’s Castle), Bottom (A Midsummer Night’s Dream) and Lady Bracknell. He performs widely in concert and oratorio.