His professional operatic conducting debut was for Verdi's La Traviata in Oviedo, Spain, in 1991, replacing a conductor at short notice.
From 1999 to 2004, de Billy was chief conductor of the Gran Teatre del Liceu in Barcelona, after the reopening of the theatre.
He prefers the smaller opera theatres (Theater an der Wien, Châtelet, Garnier), where more intimacy can be found with the audience.
[1] Since 2002, de Billy has served as chief conductor of the Vienna Radio Symphony Orchestra (RSO Wien).
In January 2009, the RSO Wien announced the appointment of Cornelius Meister as its seventh chief conductor, effective with the 2010–2011 season.