 With the ensemble and other orchestras Bernas has worked with many leading composers.World premieres he has conducted have included Gavin Bryars' opera "Medea" (1984 Lyon and Paris Operas), of which he is also the dedicatee, Nicholas Maw's "Odyssey" (1989 Royal Festival Hall), James Dillon’s "Oceanos" (1996 BBC Proms) John Casken's "Golem" (1989 Almeida Opera) as well as newly commissioned ballets for The Royal Ballet at Covent Garden, where he has been a guest conductor since 1988.Other theatre work includes Mozart's "Idomeneo" for the Theatre du Capitole, Toulouse (2000), the Ravel Operas for Opera Zuid Holland (2003), Britten's "Death in Venice" (Scottish Opera 1988) and "The Prince of the Pagodas" at Covent Garden and at the MET.