Reinbert de Leeuw is a well-known conductor and pianist performing mainly contemporary music. He also taught at the Royal Conservatoire of The Hague and founded the “Dutch Charles Ives Society”.
In 1974 he founded the Schönberg Ensemble. They focus on performing works by the Second Viennese School. For the strings of the ensemble he composed the piece Etude.
Reinbert de Leeuw regularly conducts the Netherlands' major orchestras and ensembles, including the Royal Concertgebouw Orchestra, Residentie Orchestra The Hague, the Netherlands Chamber Choir and the ASKO ensemble. He is a regular guest in most European countries and the United States, Japan and Australia. Reinbert de Leeuw has been involved in various opera productions at the Dutch National Opera in Amsterdam as well as with the Nederlandse Reisopera. Productions include works by Strawinsky, Andriessen, Ligeti and Vivier. In 2011, he conducted Schoenberg's monumental Gurre-Lieder, which was the realisation of an old ambition of his.
De Leeuw was in 1992 guest artistic director of the Aldeburgh Festival and from 1994–1998 artistic director of Tanglewood Festival of Contemporary Music. He was artistic advisor for contemporary music with the Sydney Symphony Orchestra and from 2001 to 2010 he served as artistic leader at the Nederlandse Orkest- en Ensemble-Academie (NJO; Dutch Orchestra and Ensemble Academy).