Cappella Amsterdam is a professional chamber choir that was founded in 1970 by Jan Boeke. Over the past years the ensemble, under the direction of Daniel Reuss, has occupied a prominent position in the fields of both early music and the modern and contemporary repertoires. The group aims to involve a wide audience in choral music, in particular works by old and new composers from Holland. To this end Cappella Amsterdam has realised numerous projects with works by Jan Pieterszoon Sweelinck and Orlando di Lasso as well as modern compositions, often written for the choir, by Ton de Leeuw, Hans Koolmees, Robert Heppener, Peter Schat and Klaas de Vries. Jan van Vlijmen composed by order of Cappella Amsterdam Choeurs (1999), four choirs of his new opera Thyeste, which is performed for the first time on September 27, 2005 at La Monnaie in Brussels.