 Singers who have been associated with the company include Geraint Evans , Thomas Allen , Anne Evans , and Bryn Terfel . Guest artists from other countries have included Joan Hammond , Tito Gobbi and Elisabeth Söderström . Among the conductors have been Sir Charles Mackerras , Reginald Goodall , James Levine and Pierre Boulez . The company has been led since 2011 by David Pountney as chief executive and artistic director . 
 Singers <a href='null_relcl' title='1'><mark>who</mark></a><a href='been_done' title='2'><mark>have</mark></a> been associated with the company include Geraint Evans , Thomas Allen , Anne Evans , and Bryn Terfel . Guest artists from other countries <a href='been_done' title='3'><mark>have</mark></a> included Joan Hammond , Tito Gobbi and Elisabeth Söderström . Among the conductors have been Sir Charles Mackerras , Reginald Goodall , James Levine and Pierre Boulez . The company <a href='been_done' title='4'><mark>has</mark></a> been led since 2011 by David Pountney as chief executive and artistic director . 
Singers done been associated with da company include Geraint Evans , Thomas Allen , Anne Evans , and Bryn Terfel . Guest artists from other countries done included Joan Hammond , Tito Gobbi and Elisabeth Söderström . Among the conductors have been Sir Charles Mackerras , Reginald Goodall , James Levine and Pierre Boulez . The company done been led since 2011 by David Pountney as chief executive and artistic director .