Named one of the ten best choirs in the world, the Berlin RIAS Chamber Choir (RIAS Kammerchor) is generally acclaimed as a choir of top international reputation. It has been notable for virtuoso performances of difficult new works, and increasingly for its explorations of early music. It has appeared both a cappella and with Germany's top orchestral ensembles and conductors. The Berlin RIAS Chamber Choir was formed in 1948 in a city still under divided military rule. The initials RIAS stand for Rundfunk in der Amerikanischen Sektor, or Radio in the American Sector. From the start, the choir played a key cultural role in the recovering city of Berlin; under conductors Herbert Froitzheim (1948-1954) and Günther Arndt, the group established comprehensive educational programs that included presentations in schools and academies for the training of young singers. Under Uwe Gronostay (1972-1986) and British-born Marcus Creed (1987-2001), the choir built an international reputation, resting on historically accurate interpretations of Renaissance and Baroque works, and, increasingly, on the performance of new works written for the choir itself. These have included pieces by Pierre Boulez, Hans Werner Henze, Ernst Krenek, and Paul Hindemith, among others. The choir has also been visible at major orchestral concerts, including one marking the opening of the Berlin Philharmonie (Herbert von Karajan conducted the choir in a performance of Beethoven's Symphony No. 9). Contemporary conductors have included Daniel Reuss (2001-2006), who favored early music and brought in top conductors of the historical-performance movement like Philippe Herreweghe, John Eliot Gardiner, René Jacobs, and others -- as collaborators; Hans-Christoph Rademann (2007-2015), who emphasized German repertory; and, since 2017, Justin Doyle. The choir consists of 35 singers, all professionally trained, and performs a regular concert series at the Philharmonie in addition to periodic tours. The Berlin RIAS Chamber Choir has been unusually prolific as a recording ensemble, issuing more than 50 albums. Many are on the German branch of the Harmonia Mundi label; these included, in 2019, a recording under Doyle of Benjamin Britten's Hymn to St. Cecilia.