Since 1989, the city invites international choirs, organists, singers and famous ensembles (The Hilliards, Ton Koopman, Philippe Herreweghe) to perform sacred music at the annual festival. More than 20 concerts attract an international audience of 15,000 peo-ple during July and August every year. The programme offers a broad variety of events: early, ancient and contemporary church music, gospel, jazz, world music, dance and performance art. The concerts are mostly broadcast on the radio. Additionally, the festival offers master classes and international competitions for composing and organ improvisation.